First, create a basic Alexa routine where the “when this happens” routine trigger is you saying “Alexa, I’m leaving.” Here are simple instructions for creating an Alexa routine: https://voicebrew.com/alexa-day-30/alexa-routine#basic-set-up
To set Guard to “Away” as part of your Alexa routine, when you select “Add action” tap “Guard” and then “Next.”
If you want to add playing music or radio, you can add those actions as well. If the radio station is an Alexa skill, tap “Skills” and then “Your Skills” to turn it on.
Add as many routine actions as you’d like!