Use an Apple wireless keyboard, mouse, or trackpad with Mac
Your Apple wireless keyboard, mouse, and trackpad use Bluetooth to communicate with your Mac.
Make sure the device you’re setting up has charged batteries and is turned on.
On your Mac, choose Apple menu
in the sidebar. (You may need to scroll down.)Hold the pointer over the keyboard, mouse, or trackpad in the list, then click Connect.
Note: If the device has a built-in battery, it automatically connects with your Mac when it’s turned on and its Lightning to USB Cable is plugged into your Mac.
Keep these things in mind when using an Apple Bluetooth device:
If your Bluetooth device uses AA batteries, you receive a warning when the batteries are running low; it’s a good idea to have a spare set of batteries available.
If you won’t be using your Bluetooth device for an extended period, turn it off to maximize battery life. To turn it off, use the on/off switch.