FaceTime recording - get an old Mac
If you want to automatically record FaceTime calls - incoming or outgoing - get a Mac that can handle High Sierra and install eCamm Call Recorder. Done. Any way you want it including two track - local and remote separate. And it's not a screen recording either. Example: get a 2018 MacBook Pro, add one volume for High Sierra and one for the latest Mac OS for other apps that require it.