Don't we use Tailscale for this?
Or ngrok, or Cloudflare Tunnel or https://github.com/anderspitman/awesome-tunneling
I'm gonna add https://localhost.run as a contender.
Unlike tailscale/ngrok, malai is completely open source, does not rely on any company provided infrastructure (we have a http bridge to bridge http/tcp with http/kulfi at *.kulfi.site, but you can run your own http bridge), and once Kulfi app is ready, you will not need the bridge at all and Kulfi app (which is also basically a browser that speaks http(s) over kulfi along with http(s) over tcp) can talk kulfi protocol directly.
Among other clear differences, it looks like tailscale requires you to sign in with some cloud provider and Malai does not.
I use and like tailscale for similar purposes, but I can see why some people might prefer to skip that aspect, especially.
Tailscale serve is within your tailnet
Tailscale funnel is publicly accessible