FaceTime audio and video call requirements
To make FaceTime audio and video calls on your Mac (OS X 10.9 or later required), you must meet the following requirements:
Be connected to the Internet
Be signed in to FaceTime with your Apple ID
If you don’t have an Apple ID, go to the Apple ID account website to sign up for one for free.
Have a built-in or connected microphone; for FaceTime video calls, you also need a built-in or connected camera
The person you’re making a FaceTime video or audio call to must be signed in to FaceTime and have any of the following:
A Mac with OS X 10.9.2 or later, and a built-in or connected microphone
An iOS device with iOS 7 or later or an iPadOS device