Stretched resolution help

I am on lubunto 20,04. I want to play games on a 800-600 stretched resolution. I know how to change the resolution on monitor settings but not how to stretch it. Any help would be appreciated, sorry for noob question.

I tried doing it in nvidea x server settings but I don’t know how

What kind of games are we talking about? Are you using something like DOSBox to play old games or something of that nature?