Fullscreen Widget?

Hey, I’m having a hard time making my widget take up the entire screen. I need to be able, with the press of a button, pause the game and play a fullscreen video, except I’m having two problems

A) The video doesn’t take up the entire height of the screen, leaving the level visible on the tops and bottoms of the screen. Is there a way to put black here instead?

B) The video does not show up at all on Mobile preview and this has to be a thing.