Just zoom in (or crop) and save

Hello all. Please forgive me, I’m sure this has been answered before but I’ve been searching for hours with no luck. All I want to do is zoom in on the bottom left quarter of my video and save that as the whole video. Can anyone tell me how to do this? It seems like it should be simple but I can’t do it. Thanks.

Thank you, that worked. I was trying to use the zoom control, and it zoomed but wouldn’t save.