The answer to this is a bit dicey. Or nuanced. But the explanation is worth it for your safety.
The Basics
Facetime is an Apple-owned iOS app that allows you to video chat with people on their iPhones and iPads,. To date, Facetime has only been able to connect you with other iOS devices. That means if you’re on an Android phone or a Windows computer, you can’t use Facetime!
Upcoming Changes
But in the near future, the iOS on modern iPhones and Apple tablets is going to update to version 15. And that update includes a nice change to Facetime: You’ll then be able to send invite links to non-Apple users, and rope them into your Facetime video chats!
There’s nothing to install, when you do this. Non-Apple users will receive a link that opens the Facetime chat in a browser window. It will probably be similar to receiving a Zoom link. PC and Android users will (still) not be able to initiate a Facetime chat, as only iOS users get to do that.
Why Is This Important?
Unfortunately, the nuance of what’s developing is getting lost in the headlines. Many tech articles are already cheerleading with “Facetime Coming to Windows” and that isn’t exactly true. And it is leading people down bad paths.
When some folks see that kind of news, they immediately search the internet for “Facetime for Windows” or similar. And they find free programs or extensions that claim it will install Facetime on your device. And this leads to an infection or adware getting on their machines.
Please do not install anything that says you can put Facetime on your non-Apple device. It is surely false and will only cause you trouble.