The Speaker Notes pane is the place to jot down things you want to cover when delivering your presentation. Here’s how to show or hide the Notes pane in PowerPoint Online:
On the View tab of the ribbon, in the Show group, select Notes .
The pane appears across the bottom portion of the PowerPoint window, with cursor blinking, ready for you to begin typing.
The size of the Notes pane can't be changed, but a vertical scroll bar appears on the right side if your notes exceed the allotted size of the pane.
PowerPoint Online isn't able to print speaker notes.