I can only see mention of restrictions on mobile devices on Apple's document about this, so I don't know about Macs. If you find out, let us know. Even then, the mobile device page appears to be outdated.
Find or restore a missing FaceTime app - Apple Support
"Make sure that your device supports FaceTime. FaceTime isn’t available or might not appear on some iPhones and iPads purchased or used in Saudi Arabia, Pakistan, and United Arab Emirates, including Dubai."
Document last updated October 19, 2019
BUT:
https://www.macrumors.com/2020/07/15/ios-13-6-uae-facetime-enabled/
Apple's iOS 13.6 update, released today, appears to enable FaceTime in the United Arab Emirates, a country where the FaceTime app was previously unavailable for use.