The onn boxes run android so it’s just installed as an app from play store. They connect with their own tailscale account. My server is shared so they see it. Then they install jellyfin on the device, punch in the hostname of the server given by tailscale and the port and then it connects.

I could not get my reverse proxy to let them use my local domain… I’m not smart enough and couldn’t figure it out but they are only using jellyfin so typing one address was fine.