Undo
To undo an action, double-tap the screen with two fingers.
※ If you are using the 2-page/4-page view mode, make sure to double-tap the specific page where you want to undo.
Redo
To redo an action, double-tap the screen with three fingers.
※ If you are in the 2-page/4-page view mode, remember to double-tap the desired page where you want to redo the action.