I am one that needs my notes in front of me when I present. Whether I look at them or not, it makes me feel more secure if they are there.
I have been doing a lot of presentations on Zoom using Keynote. In order to see my notes, I have had to use two monitors. Of course, when I push Play in Keynote in real life, I see my notes and the audience sees the presentation on the "big screen".
In Zoom, I share the window of the the external monitor, that has the presentation showing, with the audience and I see my notes in front of me. I do see my video and can open the chat if I need to. However, there are sometimes problems directing the audio so both the audience and I can hear me speaking and any video sound.
I finally have come up with a one-computer solution to the problem!
Here are the instructions followed by screenshots.