[Help] I cant hide the title bar in VR preview

I have a school exhibition starting tomorrow and the projector I am using is a different size from the viewport resolution of the game I am making. I am trying to make a completely black border around my screen. I managed to get rid of the windows toolbar and I made my desktop background black, but I can’t get rid of the title bar at the top of the VR preview window. I tried the borderless window setting in the project settings but it didn’t work.