Embed live camera in Keynote presentation

In these times where we give plenty of presentations from home over video conference, by sharing our screens, I am looking for a way to embed a view of my live FaceTime camera in my Keynote presentation.

I vaguely remember being able to make a Quicktime movie with a live camera feed using Quartz Composer, but I have not been able to replicate that, nor have I found any info about that, so do I misremember?

The best I have found so far is to open PhotoBooth side by side with Keynote, and to move from slide to slide like this. People watching my screen then see both my slide and me. But I can't go into presentation mode, because then the live video feed is hidden.

Perhaps if I could have a floating window with a live camera view?

Any better suggestion to achieve this effect of having the speaker face live on the shared screen while going through slides?

You can play your presentation in a window. This Keynote window can then go full screen with Photo Booth in split screen to one side, or as a normal window as you've been doing with Keynote in editing view.

To play your presentation in a window, choose Play > Play Slideshow in Window (from the Play menu at the top of your screen).

https://support.apple.com/en-gb/guide/keynote/tana4da2681/mac