How do you write a script for a game jfc

I know it probably isn't too different of a process compared to writing a movie script or comics, but for some reason my mind can't wrap around it ?? Though, to be fair I've just been relying on my mind and memory when having to move a story forward on other projects, so this would technically be the first script I would be working on...

Honestly, I think I work best when I just write things down physically rather than on an app or something. So, um umm I'm just gonna do that ehhh later