GL-MT300N-V2 MQTT function

I like to get information from the Mango over mqtt to my broker. The broker is running on a raspberry PI3

When i found and enable the mqtt feature of the Mango i could not found any informationen whre i can setup it. Also not a hwotodo decription or samples.
Have anyone use mqtt as a slave and could me help to understand how it works?

This is the tutorial about send message to AWS IoT over MQTT, hope it will help you.