A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
I have the same problem.
I had already read the page you linked to - the instructions to turn on ink replay only work for a PC. I can see no ink replay option to turn on.
As the OP noted, ink replay is apparently available on Mac (I'm using powerpoint 16.38). I'm logged in through a Microsoft 365 subscription, set as "office insider".
I tried reinstalling my O365 apps
Any other ideas?