why doesnt my iphone recognize another iphone
My iPhone 7plus doesn't recognize another iPhone 6
You must log in at Settings/FaceTime with your Apple ID and the other phone must also be logged in with it's owner's Apple ID. To activate FaceTime your account must have international text messaging enabled, as the activation process requires an invisible text to be sent to Apple's FaceTime/iMessage server in the UK. And both phones cannot have been purchased for Saudi Arabia or UAE, where FaceTime is banned.