RAK7240 Steps to configure to a MQTT broker

Please can someone explain complet and in detail how I configure 7240 RAK how I must configure it to receive a Lora data informationusing LORA channel and forward the packet to a broker MQTT which reside in RAK7240 which can be accesed by an application which will be running in a LAN with MQTT’s RAK7420.

Best regards
MIhai N