how do i turn a game to the other end of the ipad?

A portrait positioned game always starts with the bottom of the portrait on the charge connecting side of the ipad. Does anyone know how to turn the game around so that the bottom is at the picture taking end? I’ve turned the ipad and it works with a few games but not many. I’d like to be able to plug the ipad in, to recharge, and be able to play without bending the cord against my belly.