You'll need to unlock the phone using Face ID, Touch ID or your passcode. If it opens the home screen, swipe down from the center-top of the screen (not the right edge, which brings up Control Center.

That said, once you’re in the Shorts player, you can just swipe up to load a new random Short (although longer videos won’t show up this way). Sadly, 9to5Google doesn’t mention any way to ...