Custom Sensor for Custom Security System

I have an automation that essentially “trips” my custom security system as a warning. This gives me time to turn it off via siri/homekit (I have a switch in HA that is in HomeKit). It just plays a little warning sound on my Unifi cams until it turns off. When this automation is triggered, I want to update a sensor so that I can have that sensor in HomeKit and receive a notification on my phone. I get I can have a notification to the HA app, but the wife doesn’t want any part in that.

I have seen some stuff on updating the YAML, but not sure where to begin. Help! Thanks :slight_smile: