This is a minimalistic python script which I use to watch series/movies....
add your login and server in the .py file
best with
demuxer-max-bytes=1000MiB
save-position-on-quit
prefetch-playlist=yes
in ~/.config/mpv/mpv.conf
not everything implemented yet like audiobooks and whatever
All credit goes to https://github.com/jellyfin/jellyfin-apiclient-python