Background fetch: Make a request to server which contains some parameters and get response in json object using NSURLSession

I know this kind of questions are present but after searching and trying different ways whole day I didn't got success. My task is when my application receives silent push notification I want to request to my server using NSURLSession, request will contains some parameters which I need to send to my server after that my server will send response in json. How to achieve this? Not getting any way to do this if any one having idea please share with me. Code with use of AFNetworking will be more helpful.