HA+node-red: read csvdata?

I use a csv node.

I set Filename to csvdata.csv ** no absolute path specified **
no success trying multiple directories

question: What is the default directory?

With Filename to /my/path/csvdata.csv
no success

example (machine Synology + Home Assistant + Node-red)
[{"id":"73e4e16.4d9742","type":"inject","z":"8ff6ebb0.503a28","name":"Inject","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":290,"y":380,"wires":[["2bef78fd.ae70f8"]]},{"id":"90ed51dc.dcc71","type":"csv","z":"8ff6ebb0.503a28","name":"","sep":",","hdrin":true,"hdrout":"none","multi":"one","ret":"\r\n","temp":"","skip":"1","strings":true,"include_empty_strings":true,"include_null_values":true,"x":590,"y":380,"wires":[["813cb5fe.d4b2e8"]]},{"id":"9aace6e7.adc538","type":"debug","z":"8ff6ebb0.503a28","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":930,"y":380,"wires":},{"id":"2bef78fd.ae70f8","type":"template","z":"8ff6ebb0.503a28","name":"CSV data","field":"payload","fieldType":"msg","format":"handlebars","syntax":"mustache","template":"# This is some random data\na,b,c\n80,18,2\n52,36,10\n91,18,61\n32,47,65","output":"str","x":440,"y":380,"wires":[["90ed51dc.dcc71"]]},{"id":"813cb5fe.d4b2e8","type":"file in","z":"8ff6ebb0.503a28","name":"","filename":"/sv.txt","format":"utf8","chunk":false,"sendError":false,"encoding":"none","x":750,"y":380,"wires":[["9aace6e7.adc538"]]}]

Hints?

are you running NR in a docker container ?

Sincerely, I do not know.

I have a Synology station with Home Assistant installed.

I have access to node-red, influxdb, grafana, smartthings etc.

At first glance everything seems to work.