Presenter view
Can I be in presenter mode on my new MacBook Air (2020) and just have the current slide showing on the external monitor? I can do this in PowerPoint but I’d rather use Keynote.
MacBook Air
That is exactly how Keynote is designed to work:
1 - Connect a second display to the Mac, is powered on and has the input selected for the Mac
2 - go to Apple Menu > System Preferences > Displays > Arrangement: deselect the mirror option
3 - go to Keynote Preferences > Slideshow: select the option for; Enable Presenter Display
4 - If Presenter Display is showing on the wrong display, swap displays by pressing the X key on the keyboard