CasaOS and PocketBase settings

[Virgus]

Hello everybody,
I'm a new UpSnap user and I love it ! Being able finally to boot and shutdown my PCs via ZeroTier is great !

I'm using CasaOS on my Raspberry Pi as a Docker manager.
Whenever I modify the app settings in CasaOS the container is rebuilt and I loose all my configuration.
I'd like to know how to expose correctly the PocketBase settings data to an external volume.

In my CasaOS compose exported yaml, the volumes section is as follows, according to what is mentioned here :

    volumes:
      - type: bind
        source: /DATA/AppData/upsnap
        target: /app/pb_data:rw

But /DATA/AppData/upsnap directory is empty. How should I correct the compose file to fix this ?
Any suggestion would be really appreciated.
Thanks !

BTW I'm having issues with switching themes: whatever I choose I'm having always the light theme. Is there a way to force the dark theme by default ?