That doesn’t slove the problem if your Smart TV doesn’t support tailscale or something like Wireguard. Using another machine connected to a VPN like for example Tailscale/Headscale and then using ssh portforwarding allows you to access the service(jellyfin) on the device without support.

It would be like this:

Jellyfin <-- Tailscale/Headscale <— Machine forwarding the jellyfins port <-- Smart TV

This can be done with a command like this:

ssh -L 0.0.0.0:8096:jellyfin_tailnet_ip:8096 -f -N user@machine