The simplest way to undo text in Apple’s Notes app

Shake and swipe to undo on iOS and iPadOS

If you prefer using your whole hand instead of one finger, you can shake your iPhone or iPad three times. This will bring up a dialog box that asks if you want to undo what you’ve typed. Shake it three more times to bring up an option to redo typing. You can turn this capability on or off by going to Settings > Accessibility > Touch and tapping the toggle switch next to Shake to Undo.

The middle ground between your entire hand and one finger involves swiping across your phone or tablet screen with three fingers. Quickly drag your fingers to the left to undo, or to the right to redo. This gesture will work anywhere on the screen, but try to stay on top of the note—you risk hitting keys if you brush your fingers across the keyboard.