How to get JSON response data from shared class to ViewController?

I'm not using Alamofire, so i want to use JSON post approach in SharedClass and i want to send my api name and all parameters to that function. Finally i want to get the response. I tried but it's not working. If it's not correct please correct me or if any other options are available please suggest me.

My code in SharedClass

func postRequestFunction(apiName:String , parameters:String ) -> [String:Any] {

    var localURL =  "hostname/public/index.php/v/***?"

        localURL = localURL.replacingOccurrences(of: "***", with: apiName)

        var request = URLRequest(url: URL(string: localURL)!)
        request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
        request.httpMethod = "POST"
        print("shared URL : \(request)")
        request.httpBody = parameters.data(using: .utf8)

    var returnRes:[String:Any] = [:]
        let task = URLSession.shared.dataTask(with: request) { data, response, error in guard let data = data, error == nil else { // check for fundamental networking error
            print(error!)
            //                print("error=\(String(describing: error))")
                            print("localizedDescription : \(String(describing: error?.localizedDescription))")
            return
            }

            if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode != 200 { // check for http errors
                print("statusCode should be 200, but is \(httpStatus.statusCode)")
                print("response = \(String(describing: response))")
            }

            do {
                returnRes = try JSONSerialization.jsonObject(with: data, options: []) as! [String : Any]
                print(returnRes)

            } catch let error as NSError {
                print(error)
            }
        }

        task.resume()

    return returnRes
}

In my view controller class my code is. Here i'm calling function

func getProjectDetails() {
    let response = SharedClass.sharedInstance.postRequestFunction(apiName: "API Name", parameters: parameters)
    print(response)
    let res = response["Response"] as! [String:Any]
    let status = res["status"] as! String

    if status == "SUCCESS" {
        //I will handle response here
    } else {
        let message = res["message"] as! String
        //Call alert function
        SharedClass.sharedInstance.alert(view: self, title: "", message: message)
    }
}

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