Hello @Debashis Jena ,
The Azure IoT Hub supports MQTT as a transport protocol for IoT Devices.
The IoT Hub expects separate devices to communicate using specific credentials, special topics, and communication flow.
This way, you can communicate both D2C and C2D communication using MQTT
See the example on how to communicate using MQTT.
You want to connect a service to the Azure IoT Hub.
You need to add logic between the two services to honor the way Azure IoT is communicating.
An alternative is 'wrapping' your Mosquitto broker in Azure IoT Edge like this.