I have this JavaScript function to exit full screen:

var exitFullScreen = function() {
  var wasFullScreen = document.fullscreenElement || document.mozFullScreenElement || document.webkitFullscreenElement || document.msFullscreenElement;

  // Exit full screen.
  if (document.exitFullscreen) {
    document.exitFullscreen();
  } else if (document.webkitExitFullscreen) { /* Safari */
    document.webkitExitFullscreen();
  } else if (document.msExitFullscreen) { /* IE11 */
    document.msExitFullscreen();
  }
  return wasFullScreen;
}

This function works on macOS Safari. On iPhone Safari (iOS 12.5.2), it does not work, and the video element remains fullscreen.

How can I code a function to exit full screen on iPhone Safari, and if possible on all other browsers?