When trying to use Apple’s Magic Keyboard with Touch ID to authenticate for Apple Pay, publications like 9to5Mac and Macworld have reported some irregularities.
Essentially, it won’t work if someone is trying to do with a MacBook that has its display closed, as it would while operating in “clamshell mode” attached to the external monitor.
Obviously, when the MacBook cover is closed, one cannot use the built-in Touch ID sensor, so it is easy to see how this is put into place. But in a world where Apple is selling an external keyboard with a sensor (starting at a $ 150 headset), it is a worrying average. That is especially true given that the Touch ID keyboard function only works with Apple Silicon-powered Macs and comes with all but level-level iMac. That means most buyers are likely to be laptop users looking for a way to enter while their laptop is docked (perhaps even with a lock screen).
Hopefully Apple will let its users make payments with their external keypad soon, regardless of the status of their laptop cover. It is understandable that Apple wants to make sure that payment verification is a secure process – Macworld’s article mentions the load of other security settings that may affect the ability to use Touch ID with Apple Pay – but if it is safe enough to use with the M1 Mac Mini, it should be safe enough to use with a dedicated laptop.