Hi @MPand, you can use the SSH action in Siri Shortcuts to directly retrieve and execute a Keyboard Maestro macro or macro group.
You can see an example of how I unlock my Mac's via a Siri shortcut here:
Using the Siri shortcuts, I also lock the Macs again or start a backup / synchronization and much more.
You are spoilt for choice 
It is in German, but the procedure should be understandable as well 