How to make video calls between Apple phones?

When making a video call on the iPhone, you can use Face Time, enter the settings of the iPhone, and find "Face Time Call" to turn it on or off.

Usage: Find the person you want to contact in the address book, and then click the FaceTime button below the number. You can also switch to FaceTime video call during voice call, just click the FaceTime button on the phone screen. After the other party receives the invitation, the invitation will pop up on the device, and the other party can make a video call after accepting it.