Using Syncthing with Jellyfin

Hello, I am trying to sync my Jellyfin folder with all my music between my computer and my Umbrel. Using Syncthing should do the trick, but I cannot get any of the folders created by Syncthing to display in Jellyfin. Any way to fix this?
Even using already existing folders, I get either “folder path missing” or “permission denied”, even when trying to create folders in the downloads folder.

Any ideas on how to fix this?