I want to upload a file to sharepoint by microsoft, but I don't know how to do it. Specifically I want to upload a pdf file.I read a post with a flow that uses the http request but I guess that it only works to publish data to a list. Can you give some advices to do it?
In SharePoint, a document library is a list.
Are you using SharePoint on-premise or Office 365?
I'm using SharePoint, but how can I upload a file into it? I'm accessing to SharePoint trough my Office 365
For SharePoint Online (Office 365), you need to set up and register your app using the libraries that Microsoft provide for accessing SharePoint from a node.js app (which is what Node-RED is).
Note that the owner of the tenancy has to permit you to do this and the system admin will need to register your app.
There is a LOT of documentation provided by Microsoft and you will need to do some research.