Mac In Cloud.
You will need to pair your Windows machine to a Mac.
To set up the Mac build host, first enable remote login:
Make sure that it is configured to allow access for All users, or that your Mac username or group is included in the list of allowed users.
Now that remote login is enabled, connect Visual Studio 2019 to the Mac.
In Visual Studio 2019, open an existing iOS project or create a new one by choosing File > New > Project and then selecting an iOS project template.
Open the Pair to Mac dialog.
The Pair to Mac dialog displays a list of all previously-connected and currently-available Mac build hosts:
Connect to the Mac and enter your username and password when prompted.
If you have successfully paired to a Mac build host, you are ready to build Xamarin.iOS apps in Visual Studio 2019.