Error in JSON Body of HTTP

I am saving a Task number in a variable which needs to be provided in JSON body of HTTP request. Instead of providing variable directly in JSON Body, i am providing JSONBody in config file like Key: JSON Body and Value: {“u_number”:“+strTask+”,“u_state”:“Closed Complete”,“u_close_notes”:“Success”}
Here StrTask is a variable in which i am storing a task number in UiPath code. When i execute the code, STRTASK should be substituted with the value, but it isn’t and the response content of the HTTP request is:“ROW TRANSFORM IGNORED BY ON BEFORE SCRIPT”

we cannot bypass compilation.

One of more options could be:

Config File: {{"u_number":"{0}","u_state":"Closed Complete","u_close_notes":"Success"}}

Then used it within a String.Format(YourStringVar, tasknumberVar)