How-to-test-Azure-Iot-with-MQTT.md

@@ -54,3 +54,9 @@ You will be asked for enter the hours of the expiration.
 open the powershell for windows, use Azure CLI to enter the command and listen to the events:
 
 ![批注_2020-03-04_181648](uploads/956f4cb856db7d38bb7adb508607da3f/批注_2020-03-04_181648.png)
+
+## 7. For testing the subscription of topic
+
+use VSCode Azure Extension to send "Cloud to Device" message, and see what happends on the device
+
+![批注_2020-03-04_181933](uploads/e52e36990977280c40137dfa6246c677/批注_2020-03-04_181933.png)