Access to service from the internet

I'm running Windows 11 on Parallels, on an M2 Mac. I have IceCast installed and running, and can access it from the Parallels IP address from both the Mac, and the Windows UI.
How do I set it up so that it can be seen from the Internet? I have the Router set to pass the appropriate port - Port Forwarding - but it doesn't seem to work. What do I need to do. Some sort of route from the mac to the Parallels I guess?