Use the FaceTime app add reactions with hand gestures.
tvOS 17.2 or later and one of the following: iPhone XR or later (including iPhone SE 2nd generation) with iOS 17; iPad (8th generation and later), iPad mini (5th generation and later), iPad Air (3rd generation and later), iPad Pro 11-inch (1st generation and later), or iPad Pro 12.9-inch (3rd generation and later) with iPadOS 17.2.