They tell me that a "live photo" consists of a high res frame (called the key frame) together with some low res video frames.

I need help extracting the key frame for use elsewhere and for saving.

All the Google help I see tells me to select on arbitrary frame as a new key frame which is not what I want because I will certaily choose a low res frame.

Not interested in picking the frame with the best composition like nobody blinked their eyes. Just want the frame the camera saved as hi-res.