We will use the command-line tool, iothub-explorer in this recipe: Install iothub-explorer tool by following the link: https://github.com/azure/iothub-explorer. Connect to the IoT Hub using the connection string: iothub-explorer login ‘<IoTHubConnectionString> We will try and send a cloud-to-device message using this command: iothub-explorer send myFirstDevice "Hello IoT Device"