How to get rid of the “Fullscreen” button?

I want to post a high quality video that’s 1:1 ratio but when I post it like that the Fullscreen button pops up under it and it kinda ruins the aesthetic of the edit. Is there a way to bypass it. Yes I know I can make it 9:16 with black bars but it lowers the quality like crazy. Is there any other way to post 1:1 and not have that button pops up?