On the Slim X1 Bluetooth Backlit Keyboard, the F4 key is set to App Switcher on macOS. You can assign Mission Control to the F4 key in your Mac settings.

1. Open System Preferences on your Mac.
2. Go to Mission Control.
3. Next to Mission Control, select the F4 key from the dropdown list. You can also select a different key from the list.
4. Hold Fn while pressing F4 to use Mission Control. Holding Fn overrides the App Switcher shortcut already programmed on the key.