Apple’s Keyboard Assistant is responsible for setting up your external keyboard, and it doesn’t really require your help. However, if there’s an issue such as wrong keyboard layout or keyboard not working, you might need to reset it manually. Here’s how:
Disconnect the external keyboard from your MacBook
In Finder, choose your hard drive under Devices
Open the Library folder > Preferences
Find the file named ‘com.apple.keyboardtype.plist’ and delete it
Empty the Bin
Reconnect your external keyboard and let Keyboard Setup Assistant set it up.