Alternatively, you can press ⌘ Command + F3.

For a demonstration of the gesture, click on the Apple icon in the top left corner of the menu bar. Click System Preferences. Click the “Trackpad” icon. Click More Gestures. Click on “Show Desktop. " An example animation will play on the right side of the window.

If you’re using an “F” function key, you will have to hold down the Fn key to type your command.