I host a couple services for my family using a reverse proxy (nginx through SWAG), and I have a free domain name with duckdns. This is not as secure as the above tailscale solution, but has worked for me so far. This is likely how I would add Jellyfin to my workflow, since I already have a reverse proxy and domain name.
Honestly the others in this comment section would be better to ask about accessing Jellyfin remotely, but I can tell you what I know.
If you go the VPN route, Tailscale is typically recommended, which appears to be free for personal use. It looks like these are the docs for using Tailscale with Jellyfin.
I host a couple services for my family using a reverse proxy (nginx through SWAG), and I have a free domain name with duckdns. This is not as secure as the above tailscale solution, but has worked for me so far. This is likely how I would add Jellyfin to my workflow, since I already have a reverse proxy and domain name.