It's another bit on non-obvious design. You'd expect the big "button" with the off/on symbol to actually do something, but no, it's just a graphic, and you have to touch the much smaller text below it to take you to another screen where you select the one and only key to get yet another screen to actually do something (or not in my case because it doesn't work!).
Honestly, send the devs back to do some high school IT classes.
The "button" should take you directly to the actions screen (if the key is enabled), the Digital Key Management should be removed from this screen, and put back in the profile settings, where you can create/enable/disable the key.