I tested the Audio Zoom on my iPhone 11 Pro Max on iPhone System Camera App and other popular apps on the App Store (Instagram, ProCam, Moment Lens App, ..). I also tried WWDC19 session demo AVMultiCamPiP and AVCamBuildingACameraApp, which turn out to be not support Audio Zoom as well.
From my tests so far, it seems only Apple System Camera can support Audio Zoom.
My question is:
Is there any way that I can turn Audio Zoom on in my app?