Mac/Powerpoint and Zoom

I suggest you do it the exact same way you'd do it if you were presenting in loco: add a second display to your mac.

Share the second display with your Zoom audience. Done.

This is how I have been using Zoom for the last four months, and it works great.

[I only did this once using Powerpoint itself, because in my classes I use LaTeX, but the point is this works, regardless of the presentation software]

It also allows you to have other stuff on your screen that you do not care to share with the other participants.

We can argue back and forth about who knows more but I'd bet that Zoom knows more about their product and how it works and Microsoft knows more about their product and how it works. I can not imagine what the MacOS has to do with these products' configuration and operation.

Personally I would use TeamViewer to accomplish the task. But once again, TeamViewer would know how their product works.

As neither are Apple products, this is a question better directed to these vendors' site support forums.