MQTT Transmission uses Sparkplug, which defines the topic namespace and payload definition for messages over MQTT. By nature, this means that messages will be published against the following topics, based on Group ID, Edge Node ID, and optionally Device ID:
spBv1.0/<Group ID>/<Message Type>/<Edge Node ID>[/<Device ID>]
I’m not experienced with Cirrus Link’s AWS modules, but perhaps those might help you… Worth taking a look if you’re not aware of them yet.