Why don’t I have the FaceTime app in my phone ??

Where was the phone purchased? Does anything here apply to you or your phone?

FaceTime isn’t available or might not appear on devices purchased or used in Saudi Arabia, United Arab Emirates, and Pakistan. However, with iOS 11.3 and later, FaceTime is available on iPhone, iPad, and iPod touch in Saudi Arabia. And with iOS 12.4 or later, FaceTime is available on iPhone, iPad, and iPod touch in Pakistan. Update your device to get FaceTime in Saudi Arabia and Pakistan.

Please Note: If your phone was manufactured for one of the referenced countries listed above, it doesn't matter where you are currently located. A phone which was manufactured without Facetime because of governmental restrictions, will never have Facetime regardless of where the phone is begin used.