Hi faizi_968,
I had a similar kind of requirement and found this repo ( https://github.com/digidotcom/xbee-micropython/blob/master/samples/cellular/aws/aws_subscribe/main.py ) helpful. I started with the AWS IoT guide ( https://github.com/digidotcom/xbee-micropython/blob/master/samples/cellular/aws/README.md ) and on the subscription callback, just printed the received MQTT message to the specific UART port. This approach assumes the DigiXbee 3G module supports micropython.