Using Apple Pay and Touch ID on an external Magic Keyboard can get complicated
Publications like 9to5Mac and Macworld have reported some odd behavior when trying to use Apple’s Magic Keyboard with Touch ID to authenticate for Apple Pay — specifically, that it won’t work if you’re trying to do it with a MacBook that has its display closed, as it would be while running it in “clamshell mode” hooked up to an external monitor.
Obviously, when the MacBook’s lid is closed, you can’t use the built-in Touch ID sensor, so it’s easy to see how this limitation was put in place. But in a world where Apple sells an external keyboard with the sensor (starting at an eye-watering $150), it’s an awkward limitation. That’s especially true given that the keyboard’s Touch ID functionality only works with Apple Silicon-powered Macs...