Do you have a tag3? I suggest repeating the above on it. I also assume you have discovered a valid handler.
Please use the puart_control example and associated peer applications from within the SDK under: /WICED-Smart-SDK/Apps/puart_control
In addition, there is a well written document there you can reference as well: /WICED-Smart-SDK/Apps/puart_control/PUART-Control.pdf
Many of our customers and distribubtor FAEs have gotten this application up and running with no issues.