Choose how people can call you in FaceTime on Mac
When you associate email addresses and phone numbers with your Apple ID, you can specify which ones you want people to use to reach you in FaceTime. See the Apple Support article Use Continuity to connect your Mac, iPhone, iPad, iPod touch and Apple Watch.
Go to the Apple ID account website, then sign in.
In Account, click Edit, then click Add More.
Enter an email address or phone number, then click Continue.
In the FaceTime app on your Mac, choose FaceTime > Preferences, then click Settings.
Under “You can be reached for FaceTime at”, select the tickbox next to each address and phone number you want to make available for FaceTime calls.