# General

**URL:** https://discourse.nodered.org/c/general/7.md?page=564

[Latest](https://discourse.nodered.org/latest.md) · [Categories](https://discourse.nodered.org/categories.md) · [Tags](https://discourse.nodered.org/tags.md)

**Page:** 565

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## [OPC UA Certificate Issue](https://discourse.nodered.org/t/opc-ua-certificate-issue/44300)

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**Author:** [@psalibe](https://discourse.nodered.org/u/psalibe)\
**Replies:** 1\
**Last updated:** [28 April 2021 04:54 UTC](https://discourse.nodered.org/t/opc-ua-certificate-issue/44300 "2021-04-28T04:54:05Z")

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Hello, I am using the node-red-contrib-opcua nodes and trying to connect the client nodes to my OPC UA server using a certificate. I have generated the certificate on the Siemens software and set it up so that I can acc…

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## [Node-red-contrib-opcua, OPC UA server node](https://discourse.nodered.org/t/node-red-contrib-opcua-opc-ua-server-node/42442)

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**Author:** [@Tadahiro](https://discourse.nodered.org/u/Tadahiro)\
**Replies:** 1\
**Last updated:** [28 April 2021 04:51 UTC](https://discourse.nodered.org/t/node-red-contrib-opcua-opc-ua-server-node/42442 "2021-04-28T04:51:02Z")

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Dear All, I'd like to set up an OPC UA server with a node 'OPC UA server' from node-red-contrib-opcua. I just set 53880 to the port number and deployed it. But, status indicator below the node shows 'Not running'. I …

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## [Error with OPC UA nodes connectivity](https://discourse.nodered.org/t/error-with-opc-ua-nodes-connectivity/16434)

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**Author:** [@Piyush](https://discourse.nodered.org/u/Piyush)\
**Replies:** 5\
**Last updated:** [28 April 2021 04:48 UTC](https://discourse.nodered.org/t/error-with-opc-ua-nodes-connectivity/16434 "2021-04-28T04:48:25Z")

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Hello Everyone, I'm currently developing some dashboards where we have to fetch data from OPC UA server. Although I'm able to establish the connection, I'm getting the following error in receiving data from some specifi…

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## [Node Opc-ua tags list](https://discourse.nodered.org/t/node-opc-ua-tags-list/44688)

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**Author:** [@bobfield](https://discourse.nodered.org/u/bobfield)\
**Replies:** 1\
**Last updated:** [28 April 2021 04:46 UTC](https://discourse.nodered.org/t/node-opc-ua-tags-list/44688 "2021-04-28T04:46:50Z")

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Hi Dears, I begin to use the node opc-ua to read tags from a opc-ua server. I would like to know if is possible define a msg.payload tags list to enter in an unique OPC-UA-ITEM and after in an OPC-UA-CLIENT. Reading the…

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## [Can't get SQLite to install](https://discourse.nodered.org/t/cant-get-sqlite-to-install/44515)

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**Author:** [@jrayb](https://discourse.nodered.org/u/jrayb)\
**Replies:** 3\
**Last updated:** [28 April 2021 03:17 UTC](https://discourse.nodered.org/t/cant-get-sqlite-to-install/44515 "2021-04-28T03:17:25Z")

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I have tried several options that were posted here & I cannot get the node to install. Log is below. 2021-04-22T02:05:02.537Z Install : node-red-node-sqlite 0.6.0 2021-04-22T02:05:02.599Z npm install --no-audit --no-u…

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## [No .node-red folder](https://discourse.nodered.org/t/no-node-red-folder/44728)

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**Author:** [@jake123](https://discourse.nodered.org/u/jake123)\
**Replies:** 5\
**Last updated:** [26 April 2021 16:56 UTC](https://discourse.nodered.org/t/no-node-red-folder/44728 "2021-04-26T16:56:56Z")

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I installed node-red on my new pc and i cant seem to find .node-red folder. Any idea why it isnt in my Users\\user.node-red

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## [Checking for a key with a space inside it?](https://discourse.nodered.org/t/checking-for-a-key-with-a-space-inside-it/44827)

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**Author:** [@nicedevil](https://discourse.nodered.org/u/nicedevil)\
**Replies:** 15\
**Last updated:** [27 April 2021 21:41 UTC](https://discourse.nodered.org/t/checking-for-a-key-with-a-space-inside-it/44827 "2021-04-27T21:41:10Z")

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Hi everyone, I'm getting an object with a key that got a space in its name and I'm trying to figure out how to create a switch rule for that. Here you can see an example output what I mean: And this is what I'm tryin…

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## [Merge more than 3 .csv files](https://discourse.nodered.org/t/merge-more-than-3-csv-files/44818)

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**Author:** [@Miliks](https://discourse.nodered.org/u/Miliks)\
**Replies:** 2\
**Last updated:** [27 April 2021 19:17 UTC](https://discourse.nodered.org/t/merge-more-than-3-csv-files/44818 "2021-04-27T19:17:21Z")

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I have a main.csv file with several lines (for now we can assume 3 lines - first one with the titles and 2 with the data), each data line contains some data + reference to another csv file with other details. I want to r…

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## [Error: easybotics led-matrix doesn't work](https://discourse.nodered.org/t/error-easybotics-led-matrix-doesnt-work/44756)

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**Author:** [@ronanptl](https://discourse.nodered.org/u/ronanptl)\
**Replies:** 4\
**Last updated:** [27 April 2021 17:40 UTC](https://discourse.nodered.org/t/error-easybotics-led-matrix-doesnt-work/44756 "2021-04-27T17:40:05Z")

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Hello, I've install node-red recently thanks to the following script on my raspberry pi3 b+ : bash \<(curl -sL https://raw.githubusercontent.com/node-red/linux-installers/master/deb/update-nodejs-and-nodered) node-red w…

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## [ModBus function code 23](https://discourse.nodered.org/t/modbus-function-code-23/44738)

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**Author:** [@BJM](https://discourse.nodered.org/u/BJM)\
**Replies:** 2\
**Last updated:** [27 April 2021 17:05 UTC](https://discourse.nodered.org/t/modbus-function-code-23/44738 "2021-04-27T17:05:25Z")

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We have a added a new piece of equipment and unfortunately this device only support ModBus function 23 for Writing multiple registers. The generel Modbus nodes only support code 16 for writing multiple registers, and doe…

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## [Implementing call and return](https://discourse.nodered.org/t/implementing-call-and-return/44807)

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**Author:** [@tcr000](https://discourse.nodered.org/u/tcr000)\
**Replies:** 1\
**Last updated:** [27 April 2021 16:16 UTC](https://discourse.nodered.org/t/implementing-call-and-return/44807 "2021-04-27T16:16:13Z")

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I am developing an application with several stepper motors on Raspberry Pi. Each stepper motor has its own sub-flow with inject node to update its state and handle commands (home, move, reset). Various nodes can use link…

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## [MQTT in Node Configuration](https://discourse.nodered.org/t/mqtt-in-node-configuration/44734)

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**Author:** [@edwardr](https://discourse.nodered.org/u/edwardr)\
**Replies:** 4\
**Last updated:** [27 April 2021 15:25 UTC](https://discourse.nodered.org/t/mqtt-in-node-configuration/44734 "2021-04-27T15:25:56Z")

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Hello Folks, I am trying to reduce costs using my AWS MQTT broker with Node Red. One of the ways I am hoping to do this is by creating a function filter that only posts a payload if its different to the previous messag…

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## [Run python functions by execute node](https://discourse.nodered.org/t/run-python-functions-by-execute-node/44796)

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**Author:** [@anguslou](https://discourse.nodered.org/u/anguslou)\
**Replies:** 7\
**Last updated:** [27 April 2021 15:15 UTC](https://discourse.nodered.org/t/run-python-functions-by-execute-node/44796 "2021-04-27T15:15:21Z")

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Hi, I have a python script with simple functions: import sys a = sys.argv\[1\] b = int(sys.argv\[2\]) class Hello: def \_\_init\_\_(self, a, b): self.a = a self.b = b def hello(self, a): name = 'hello, ' + self.a prin…

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## [Allow only last msg.payload to pass](https://discourse.nodered.org/t/allow-only-last-msg-payload-to-pass/44810)

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**Author:** [@sahsha](https://discourse.nodered.org/u/sahsha)\
**Replies:** 0\
**Last updated:** [27 April 2021 14:40 UTC](https://discourse.nodered.org/t/allow-only-last-msg-payload-to-pass/44810 "2021-04-27T14:40:23Z")

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Hi everyone, I need help with on how to allow only the last msg.payload to pass. I've made a flow to send email and email is comprised of data from different flows which are executed at different time and when all the v…

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## [Reading from a PN532 Reader via UARD to PI4 using Node-RED](https://discourse.nodered.org/t/reading-from-a-pn532-reader-via-uard-to-pi4-using-node-red/44808)

<div class="topic-metadata">

**Author:** [@vongomben](https://discourse.nodered.org/u/vongomben)\
**Replies:** 0\
**Last updated:** [27 April 2021 14:30 UTC](https://discourse.nodered.org/t/reading-from-a-pn532-reader-via-uard-to-pi4-using-node-red/44808 "2021-04-27T14:30:53Z")

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Hi forum. I'm trying to read the content of a Grove NFC Module from a PI4 Using Node-RED (And a Grove Hat) The device is talking Serial, and I was expecting to read it using the serial node, but this is not working. T…

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## [One github repository for docker-compose application consisting of a node-red application](https://discourse.nodered.org/t/one-github-repository-for-docker-compose-application-consisting-of-a-node-red-application/44523)

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**Author:** [@janvda](https://discourse.nodered.org/u/janvda)\
**Replies:** 8\
**Last updated:** [27 April 2021 12:46 UTC](https://discourse.nodered.org/t/one-github-repository-for-docker-compose-application-consisting-of-a-node-red-application/44523 "2021-04-27T12:46:54Z")

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The context: I am developing a docker compose application consisting of multiple services of which one (or more) service is a node-red application with its specific node-red flows. For development I am using 2 machine…

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## [How to display mqtt image on uibuilder](https://discourse.nodered.org/t/how-to-display-mqtt-image-on-uibuilder/44280)

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**Author:** [@noBody](https://discourse.nodered.org/u/noBody)\
**Replies:** 8\
**Last updated:** [27 April 2021 12:57 UTC](https://discourse.nodered.org/t/how-to-display-mqtt-image-on-uibuilder/44280 "2021-04-27T12:57:53Z")

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Hi, I can display images received via MQTT on the dashboard using ui\_template but I have to send the same image to uibuilder page. I am pretty new to js and can't seem to make it work. Can anyone provide a minimal examp…

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## [Zoom iframe possible?](https://discourse.nodered.org/t/zoom-iframe-possible/44743)

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**Author:** [@steinerma](https://discourse.nodered.org/u/steinerma)\
**Replies:** 1\
**Last updated:** [27 April 2021 12:18 UTC](https://discourse.nodered.org/t/zoom-iframe-possible/44743 "2021-04-27T12:18:10Z")

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hi, is there any way to change the zoom level from an iframe window using a variable? So I could change it in the dashboard by a button \[ { "id": "bd76668e.c11518", "type": "function", "z": "…

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## [Help with JSON Node - Schema validation](https://discourse.nodered.org/t/help-with-json-node-schema-validation/44598)

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**Author:** [@H3llsing](https://discourse.nodered.org/u/H3llsing)\
**Replies:** 8\
**Last updated:** [27 April 2021 10:03 UTC](https://discourse.nodered.org/t/help-with-json-node-schema-validation/44598 "2021-04-27T10:03:28Z")

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Hey together, i wasn't sure if this problem would fit inside https://discourse.nodered.org/t/json-node-schema-validation/2574/13 So i would like to validate json against a json schema. The JSON node comes with the abi…

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## [Door opener control](https://discourse.nodered.org/t/door-opener-control/44385)

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**Author:** [@ajocius](https://discourse.nodered.org/u/ajocius)\
**Replies:** 20\
**Last updated:** [27 April 2021 09:13 UTC](https://discourse.nodered.org/t/door-opener-control/44385 "2021-04-27T09:13:13Z")

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I have door opener that I will put on greenhouse door where I do measure temperature. Total time to fully open door is 48 sec. Thought of setting few steps so that it would open 1/4 way when temp reaches 20C, at 24C woul…

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## [Grove Base Hat and documentation](https://discourse.nodered.org/t/grove-base-hat-and-documentation/44792)

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**Author:** [@bcolias](https://discourse.nodered.org/u/bcolias)\
**Replies:** 1\
**Last updated:** [27 April 2021 09:09 UTC](https://discourse.nodered.org/t/grove-base-hat-and-documentation/44792 "2021-04-27T09:09:15Z")

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I'm trying to use the ADC that is part of Seeed's Grove Base Hat. I'm using an RPI 3+. My simple project is to read the ADC from a soil sensor. The trouble I have is a lack of documentation to refer to. The Hat uses a ST…

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## [Node-Red to join Telegram messages](https://discourse.nodered.org/t/node-red-to-join-telegram-messages/44770)

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**Author:** [@Broutech](https://discourse.nodered.org/u/Broutech)\
**Replies:** 5\
**Last updated:** [27 April 2021 08:48 UTC](https://discourse.nodered.org/t/node-red-to-join-telegram-messages/44770 "2021-04-27T08:48:41Z")

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Good day, Very recently I embarked on finding a way to ping network devices from a database or list. While pinging and a device appears offline, i then wanted to post that "offline" device to Telegram. A member on the …

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## [Node-red-contrib-opcua - connection error: end point must exist](https://discourse.nodered.org/t/node-red-contrib-opcua-connection-error-end-point-must-exist/44741)

<div class="topic-metadata">

**Author:** [@Ashkan](https://discourse.nodered.org/u/Ashkan)\
**Replies:** 10\
**Last updated:** [27 April 2021 08:27 UTC](https://discourse.nodered.org/t/node-red-contrib-opcua-connection-error-end-point-must-exist/44741 "2021-04-27T08:27:19Z")

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Hello everyone, i´m trying to connect my PLC over the Client with Node-RED. i added in my Client a Server with the correct address (hopefully :slight\_smile: )but i receive this error " Client node error on: error: \[" …

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## [How to dynamically change the configuration parameter of a mongodb database name](https://discourse.nodered.org/t/how-to-dynamically-change-the-configuration-parameter-of-a-mongodb-database-name/44747)

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**Author:** [@yakupbaltas](https://discourse.nodered.org/u/yakupbaltas)\
**Replies:** 2\
**Last updated:** [27 April 2021 05:43 UTC](https://discourse.nodered.org/t/how-to-dynamically-change-the-configuration-parameter-of-a-mongodb-database-name/44747 "2021-04-27T05:43:20Z")

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How can I change the database name that I get from the user with the node setting. Thank you all.

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## [NodeRed crashing after recent install of (?)zigbee2mqtt(?)](https://discourse.nodered.org/t/nodered-crashing-after-recent-install-of-zigbee2mqtt/44731)

<div class="topic-metadata">

**Author:** [@GeorgeCastanza](https://discourse.nodered.org/u/GeorgeCastanza)\
**Replies:** 6\
**Last updated:** [27 April 2021 04:22 UTC](https://discourse.nodered.org/t/nodered-crashing-after-recent-install-of-zigbee2mqtt/44731 "2021-04-27T04:22:57Z")

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I've had no issues for years with Node Red. However, it's crashing every couple of hours. I presume it's because of a recent install of zigbee2mqtt.....but not sure. How would I go about debugging. I've been checking th…

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## [Trading robot for forex or stock](https://discourse.nodered.org/t/trading-robot-for-forex-or-stock/42991)

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**Author:** [@anguslou](https://discourse.nodered.org/u/anguslou)\
**Replies:** 9\
**Last updated:** [27 April 2021 03:18 UTC](https://discourse.nodered.org/t/trading-robot-for-forex-or-stock/42991 "2021-04-27T03:18:30Z")

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Recently I am thinking to make a trading robot by Node-Red, surprisingly I can only find very limited information except cryptocurrency trading robot. It seems Node-Red developers are only interested in cryptocurrency bu…

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## [Uploading file http put request](https://discourse.nodered.org/t/uploading-file-http-put-request/44725)

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**Author:** [@francodutch](https://discourse.nodered.org/u/francodutch)\
**Replies:** 16\
**Last updated:** [26 April 2021 22:39 UTC](https://discourse.nodered.org/t/uploading-file-http-put-request/44725 "2021-04-26T22:39:42Z")

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Hi everyone I need some help after struggling with a topic I'm not familiar with. I want to upload a jpg to a one off signed url which I receive through mqtt. It needs to be through a PUT method. Does anyone have a worki…

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## [Graphs on power bi](https://discourse.nodered.org/t/graphs-on-power-bi/44774)

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**Author:** [@Alex95](https://discourse.nodered.org/u/Alex95)\
**Replies:** 1\
**Last updated:** [26 April 2021 20:25 UTC](https://discourse.nodered.org/t/graphs-on-power-bi/44774 "2021-04-26T20:25:46Z")

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Hello everyone. Before i tell you my question i will explain you what i have done so far. So, i have 2 Arduino which communicate via LoRa (because i have added 2 Dragino shields on Arduino). Arduino send the following da…

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## [Form-data multipart-encoded request with pdf file attached into the body](https://discourse.nodered.org/t/form-data-multipart-encoded-request-with-pdf-file-attached-into-the-body/44749)

<div class="topic-metadata">

**Author:** [@vmoscolini](https://discourse.nodered.org/u/vmoscolini)\
**Replies:** 2\
**Last updated:** [26 April 2021 14:02 UTC](https://discourse.nodered.org/t/form-data-multipart-encoded-request-with-pdf-file-attached-into-the-body/44749 "2021-04-26T14:02:14Z")

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Hi all, Introduction I need to call an API that requires to pass a pdf file into the body as form-data (Multipart-encoded - method POST). Api Details url: https://jurisfai-api.ml/submitfile method: POST body: form-…

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## [Getting weird error](https://discourse.nodered.org/t/getting-weird-error/44700)

<div class="topic-metadata">

**Author:** [@hoolahoous](https://discourse.nodered.org/u/hoolahoous)\
**Replies:** 6\
**Last updated:** [26 April 2021 19:37 UTC](https://discourse.nodered.org/t/getting-weird-error/44700 "2021-04-26T19:37:31Z")

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I have a flow where I do some HTTP post using axios library (in function node). I attached a debug node to output. Function node makes http call, and sets the result object as payload and sends it forward to debug nod…

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