To create a new video project tap the “+” sign in the lower right corner of the app screen then swipe left to put the app in video mode.
Once in recording mode you use the on-screen settings to select which camera to use (rear-facing versus front-facing), video resolution (4k* versus HD), and frame rate (30fps versus 24fps).
These settings will be maintained for any new video projects until they are adjusted again.
*4k video availability varies based on iPhone model