I build iOS apps using Visual Studio 2019 + Xamarin on Windows, then running macOS in a VMWare VM that basically just functions as a build server (Windows communicates with it via SSH). You can find lots of YouTube videos describing how to do it.
It's technically against the macOS terms of service, but the macOS terms of service are likely illegal anyways (monopoly bundling of hardware + software, etc).
I'm working on some games and apps but only publishing it for Android, cause I don't own a mac.