How to get the return response variable in restful webservice (GET)

Hi,

Currently I am experiencing an issue in restful webservice call. 
I've created an custom WF, where I am calling GET method. In the response, I have mentioned the variable name where I need to get it from the return response.

Could someone please help me if I am missing something in the configuration ?

I am getting an error as like "RSA003 : Unable to find the configured variable from the response"