Not the person you asked, but I simply put Authelia in front of Jellyfin via my reverse proxy (not using OAuth to integrate with Jellyfin), and that means that you have to be authenticated for any request on my jellyfin subdomain to be able to reach my Jellyfin server. Probably means I can’t connect via the app remotely, only browser, but then I can just use my VPN and connect directly to the local IP.