I assume, you are asking how to allow remote (as in outside of your network) access. There are multiple options to achieve this goal:
- Local reverse proxy and port forwarding: You essentially poke a hole through your firewall to expose your Jellyfin to the internet. Only works if you got a static IP and your router allows it.
- VPN: Sometimes your router has a VPN option built in. Otherwise Tailscale is a simple option. Requires some setup on the playback device. Not recommended if your users are using a lot of non-Android smart TVs
- Tunneling to remote reverse proxy: generally the recommended option. Pangolin and netbird are two providers of such services. Your users connect to their servers and then they are automatically redirected to your server. Both services are also open source, so you can selfhost that part of the setup as well, if you want (that's what I do)