You can add the following options to the start of the response:
var response = "HTTP Status: 404\r\n";
response += "Content-Type: text/plain\r\n";
response += "httpHeader: myToken:ABCDEF\r\n";
response += "This is my payload";
qie.postMessageResponse(response);
The HTTP status can return any integer value for the status code.
The Content-Type allows you to specify the payload content type.
The httpHeader can be any additional headers that are needed in the response. To specify a header, you will separate the header name (key) and the value with a colon (:).
Make sure that you have set your source node to response to "From Mapping or Destination node"

You can create a custom mapping function withe the qie.postMessageResponse(response);
