Hi, just want to clarify, are you setting up Alarm.com scenes or automation rules? Both words have been used but they are different things in ADC.
It sounds like what you are looking for is an automation rule which automatically turns off the Dome when the panel is armed from any source. Is that correct? Do you want it to always be shut off when armed?
Scenes in Alarm.com are different, where you can create a scene, define all the actions that will be taken, and then when you run that scene they will all occur. This is not automating events, it is just grouping a number of actions together.
To help clarify, this post goes over how to create automation rules (specifically based on Geo-services, but you would follow same early path and select when armed away). This post goes over how to create scenes.
I just want to be sure you’re setting up rules instead of scenes if your intention is to have this always occur no matter how the panel is armed.