I figured out how to make an iHeart Radio station trigger by Sonos alarm. This is something the Sonos community has been asking for for years on the Sonos forum. Maybe there is a reason Sonos won't do it. I won't post it there because they will block it quicker. But Google can still find it here.
Using Sonos PC controller:
Play the station you want.
Click on the radio station graphic in the Now Playing window.
A popup of the graphic will appear.
Hover over the popup and you will see an icon with the letter "i" in the bottom right corner. Press it and new commands will appear in the "Info and Options" pane. (Close the popup graphic.)
One of the commands is "Add To My Radio Stations."
You can set an alarm to a station that is in the "My Radio Stations" favorite list.
