Error: read /etc/influxdb2: is a directory

Thank you for this project
I have influxdb running in a container on a synology nas.
I would like to backup its data.
But if I run the influx- command inside the container, I get a response
`Error: read /etc/influxdb2: is a directory`
Which is true. Inside /etc/influxdb2 there is a file config.json.

Even running 'influx server-config' gives the same error.

What am I missing?
Thank you.