Thank you for this post, I tried to use this action for the first time today and it didn't work for me at first.
It turns out you need to have "Show fast user switching menu as" turned on in system preferences.
I think KM is triggering it via the manu bar is why.
I didn't see this mentioned in the Wiki so am wondering if this is a Montery thing?? I hid the icon completely w/ Bartender and it still works.