DA16200 MQTT operation

I am new to the DA16200. I have the DA16200 Eval kit. Our application requires MQTT JSON packets to be published and subscribed to. I see MQTT commands under the NET commands but I do not see any documentation in the user manual for these commands. How do I set up and publish/subscribe using MQTT? is there an MQTT example code? How do I create and format a JSON packet to publish? How is the JSON packet handled on a subscribe reception?

SDK Version     : V3.1.2.0 GEN

/DA16200/NET] # mqtt_config

- Usage: MQTT Configuration
        mqtt_config broker <Broker IP>
        mqtt_config port <Port Number> (Default: 1883)
        mqtt_config pub_topic <Topic>
        mqtt_config sub_topic_add <Topic>
        mqtt_config sub_topic_del <Topic>
        mqtt_config sub_topic <Topic Number(1~4)> <Topic#1> <Topic#2> ...
        mqtt_config qos <QoS Level> (Default: 0)
        mqtt_config tls <1|0> (Default: 0)
        mqtt_config username <Username>
        mqtt_config password <Password>
        mqtt_config long_password
        mqtt_config will_topic <Topic>
        mqtt_config will_message <Message>
        mqtt_config will_qos <QoS Level> (Default: 0)
        mqtt_config auto <1|0> (Default: 0)
        mqtt_config ping_period <period> (Default: 600)
        mqtt_config ver311 <1|0> (Default: 0)
        mqtt_config reset (Delete All Configuration)
        mqtt_config status
        mqtt_config client_id <client_id>