On iPad Air (4th generation), iPad Pro 12.9-inch (3rd generation and later), or iPad Pro 11-inch, you can turn accessibility features on or off by triple-clicking the top button.

• Set up Accessibility Shortcut: Go to Settings  > Accessibility > Accessibility Shortcut, then select the features you use the most.
• Slow down the double-click or triple-click speed for the top button: Go to Settings > Accessibility > Top Button.
• Use Accessibility Shortcut: Triple-click the top button.