A:Answer I'm not sure how you would use it with Alexa. It can be used with SmartThings, which can be connected to Alexa... But, all of the events and modifications I use this device for have been through SmartThings.
I have SmartThings, Phillips Hue, Logitech Harmony, and Alexa... and use them to control lights, entertainment center, etc...
Alexa can be used to control each of those devices verbally, but the presence sensor is only used (in my setup) as a marker for SmartThings to run events (when "x" arrives or leaves)...