How to ADD VIDEO as BACKGROUND in YOUTUBE SHORTS?

here is um youtube app and basically if you want to create shorts so basically again to create shorts just tap here in the bottom add plus create short and then uh you here you can add as a background one of your previous videos so this is basically a way to remix kind of to add the reaction to your previous videos uh on on youtube short so that's what you can do so just type here that's the idea so for example and then i can just select this some small episode from it yeah it just takes time it can be a bit buggy but yeah overall that's basically the idea