Running commands on Raspberry Pi gateway

Goodmorning everyone.
I am writing to you because I need help.
I would like to run a shell command on a rak831 gateway installed on raspberry connected to the internet with a GSM modem.
I thought about using the mqtt protocol but I have no idea how to do it.
Someone has an advice
Thank you

Hi Silvano,

I think you will have to use UDP to talk to lora_gateway_bridge here.

RAK831 with RPi should send UDP message to lora_gateway_bridge, and bridge will send MQTT message to broker, then lora server and lora app server will subscribe MQTT message