Installing 3CX on Windows is supported (whether local or cloud) so long as it is one of the below versions https://www.3cx.com/docs/manual/
Debian is much more efficient on resources though so it makes more sense on cloud machines where you would not want to pay for extra resources just to be "eaten up" by the OS without giving you anything significant back in return.
If you cannot find a way to install a 3CX supported OS, then you will have to choose a different hosting platform. Have you talked to your hosting partner? Maybe they can help you deploy your own ISO.
