From the Jellyfin documentation:
Jellyfin is designed to directly read media from the filesystem. A network storage device that is using samba or NFS must be directly mounted to the OS. The Jellyfin database should also be stored locally and not on a network storage device.
I'm a fan of linuxserver.io images - https://docs.linuxserver.io/images/docker-bookstack
From the Jellyfin documentation: