My understanding is that the Glass Break feature is only available to subscribers of Cam Protect.
I have the HMS service, so I am prohibited from also subscribing to Cam Protect. The Glass Break feature is currently not available to HMS subscribers.
I am unsure how the Glass Break feature interacts with the Noonlight Professional Monitoring Service under the Cam Protect subscription. If it is anything similar to the Smoke Detector and Carbon Monoxide Detector “listening” features on the cams under HMS, there is no link to the Noonlight Professional Monitoring Service and therefore no professional monitoring or insurance discount for these features. On the HMS, Smoke and Carbon Monoxide Alarm Sound Events are “self monitored” and result in only a Push Notification to the phone.
Adding the Glass Break feature to the HMS, along with Friendly Faces, has been requested on the Wishlist already and needs some support (low vote count). Follow the link, vote at the top, like 
some posts, and add your reply in support.