カメラ必須だと思います。 FaceAR というのは↓のことですよね？ https://developer.apple.com/documentation/arkit/arfacetrackingconfiguration

6:59 AM

Face tracking is available only on iOS devices with a front-facing TrueDepth camera (see iOS Device Compatibility Reference). Use the ARFaceTrackingConfiguration isSupported property to determine whether face tracking is available on the current device before offering the user any features that require face tracking.