I just got mine working a few months ago on FreeBSD using cloudflared. I paid for a cloudflare DNS and run cloudflared (in a jail, which is optional). Here is a redacted example of my tunnel.yml file (should work similarly on other OS's)

# cat /root/.cloudflared/fbsd0_tunnel.yml

    tunnel: <redacted UUID>

    credentials-file: /root/.cloudflared/<different UUID>.json

    ingress:

  # Example of an HTTP request over a Unix socket:

  - hostname: <redacted full cloudflare URL, no port appended>

    service: http://localhost:8096 #this is where jellyfin would normally run

  # Example of a rule responding to traffic with an HTTP status:

  - service: http_status:404