Files app on iPad Pro

Hi,

For a while now, I’m using my iPad with Magic Keyboard as my main device whenever I’m away from my desk. Overall this experience has been great, except for one thing. When opening PDFs in the files app, it automatically fills the entire screen, and I can’t seem to figure out how to zoom out without closing the entire document. I was wondering if I’m missing something as I would really like to use the files app because I think its great to mark text in. In the meantime, I’ll be using adobe, which does allow me to zoom out.