Because the feature works with Shortcuts app automations, the possibilities for iPhone 12 Back Tap custom controls are basically limited only by your imagination. If you want to stick to the basics, assign a double or triple tap on the back of your iPhone to open Control Center, take a screenshot, or enable Accessibility features like Assistive Touch, Voice Over, Zoom, and so on. However, the function is quite flexible: it may be configured for accessibility features, basic system tasks, and custom Shortcuts.
How to use iPhone Back Tap custom controls in iphone 12
Go to Settings > Accessibility on your iPhone and tap Touch. Swipe to the bottom of the screen and choose ‘Back Tap’ Tap. To choose an action, double-tap or triple-tap. Remember that you may launch automations with Shortcuts by using a Double or Triple Back Tap.