The Apple iPhone 12 Pro Max has three rear cameras with the Nomad Rugged Leather Moment case supporting Moment lenses on two of the three cameras. The top left camera on the 12 Pro Max is the telephoto lens and the bottom left camera is the standard, wide-angle lens. There is no support on this case to attach a Moment lens to the ultra-wide camera that is found on the center right of the camera area.
Even with the 0.5 ultra-wide camera on the iPhone, the 18mm wide-angle Moment lens provides a broader field-of-view.
After attaching your Moment lens, make sure to use the Moment smartphone app that gives you specific control over the lens being used for capturing content.