Information required to publish the MQTT message through the AWS IoT message broker.
The MQTT topic of the message. You can use a string expression that includes variables ($variable.<variable-name>) and input values ($input.<input-name>.<path-to-datum>) as the topic string.
$variable.<variable-name>
$input.<input-name>.<path-to-datum>
You can configure the action payload when you publish a message to an AWS IoT Core topic.