how to configure lemmy to use extra volume ?

the diskspace on the server I'm using for lemmyfly.org is getting full (it was 40GB local volume, and it's at 80% now) I can get extra volumes at my hosting (Hetzner) but is it possible lemmy looks at different volumes for the volumes folder that contains pictrs, postgres and lemmy-ui ?

Or do I need to move the complete main lemmy folder to this other volume and run lemmy from there, leaving my system-volume unused for lemmy ?