Trigger VoiceOver
If you need or want to use VoiceOver on your Mac, your Touch ID button makes it easier than you could ever imagine. All you need to do is press and hold the Command key on your keyboard and then press the Touch ID button three times. Remember to do it quickly, or you just end up locking your screen.
VoiceOver will instantly start working, and your Mac will start talking to you. If you turn VoiceOver off, just repeat the same steps mentioned above.