how to turn a video into a short on youtube

I'm trying to make some shorts on Youtube, but I can't manage to do it if the camera isn't a phone.
Why?

Can someone help me?

shorturl.at/nFIS4

Hope it helps.

@Alientcp said in #3:
> shorturl.at/nFIS4
>
> Hope it helps.
Bruh wtf was that?

@LordSupremeChess said in #4:
> Bruh wtf was that?

Help?

yeah

I dont know actually