Safe Frame from Extension Warehouse is a help. This is 4x5 vertical format 1080p wide.
Natively, MacOS and iPad can set both vertical and horizontal pixel dimensions, though without Safe Frame you won’t know exactly what you’re getting till you do it.
The vertical part of the picture is fixed, and the width varies with aspect ratio. See this thread. I’m a Mac user, but my understanding from @DaveR who does know Windows is that it can’t set both aspects, so you’re left with picking the vertical dimension pixels, accepting whatever you get horizontally and cropping it later in an image editor.