How to use Last Notification sensor

I’ve enabled the Last Notification sensor, set the allow list to a single app - the Ring app. How do I trigger on this sensor? The state is always com.ringapp once the app notification appears once. I do note that the “last updated” attribute updates, but my test automation doesn’t fire on the state.

Figured it out. You have to use a state trigger with no from or to value. It will trigger on any update at that point.

How to declare this trigger in HA please?
I wanted to declare the “Last Notification” entity at the level of my “Mobile” device in HA I activated it but it remains in the “unknown” state.
So I can’t find it in “Automation” as a “Trigger”…

Settings > Companion App > Manage Sensors > Last Notification

configure the sensor to receive data.