FaceTime not working on iPhone 7 plus

Go to Settings and tap Cellular or tap Mobile Data, then turn on FaceTime. If you're using an iPad, you might see Settings > Cellular Data. Go to Settings > FaceTime and make sure that FaceTime is on. If you see "Waiting for Activation," turn FaceTime off and then on again.

If you can't make or receive a FaceTime call on your iPhone or ...

FaceTime isn't available or might not appear on devices purchased in United Arab Emirates. Group FaceTime and FaceTime Audio are not available in China mainland on iPhone and iPad with cellular.