Here's how you can connect a wireless keyboard to your Apple TV.
1. Make sure you are running the latest version of the Apple TV operating system. a. Go to Settings. b. Go to General. c. Select Update Software. d. Select Download and Install. e. The update will be installed and your Apple TV will reboot.
2. Go to Settings.
3. Go to General.
4. Go to Bluetooth.
5. Put your wireless Apple keyboard into pairing mode by holding the power button.
6. Your keyboard will appear on the Apple TV screen, enter the pairing code to connect your keyboard to your Apple TV.
For more, see the original article at the link below.
Sync a Wireless Bluetooth Keyboard with Apple TV | OS X Daily