Keynote presentation on Zoom

I watched a video on YouTube explaining how to do a Keynote presentation on Zoom, so I could see my presenters notes but they could only see the slides. However, no matter what I do, once I click "Rehearse slideshow" I go in to full screen mode and then can't access Zoom to set it up! Plus, the YouTube video suggested using the advance setting in Zoom to only display part of the screen (ie the current slide on "Presenter view"), but I have a "button" hovering over the current slide saying "Show Navigator", which I assume would also show up on Zoom - can I stop this showing?