https://www.liveslides.com/faq/mouse-pointer-does-not-appear-in-keynote
Keynote hides the mouser pointer during a presentation by default. If you’d like to interact with the web content in your LiveSlides you will need to enable the mouse pointer with these following steps:
Select “Preferences…” from the Keynote menu
Click the “Slideshow” icon in the menu bar
In the “Interacting” section, select “Show pointer when using the mouse or trackpad”
Close out Preferences and you should now have a mouse pointer while presenting.