swift with Uploading Data to a Website not working

Question

I want to post the token to the server, but the code I wrote does not work. Post processing is not occurring. why ? Even null value does not go to server . why ? Token is global variable(string) and iself token id. For example: dchksjdjfs-123anksndjd

    override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

timer = Timer.scheduledTimer(timeInterval: 2, target: self, selector: #selector(counterFunc), userInfo: nil, repeats: true)


} 
   @objc func counterFunc() {


    guard let uploadData = try? JSONEncoder().encode(Tokeen) else {
        return
    }

    let url = URL(string: "https://...../....php")!
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    request.setValue("application/json", forHTTPHeaderField: "Content-Type")

     print ("uploadData: \(uploadData)")// is empty
    let task = URLSession.shared.uploadTask(with: request, from: uploadData) { data, response, error in
        if let error = error {
            print ("error: \(error)")
            return
        }
        guard let response = response as? HTTPURLResponse,
            (200...299).contains(response.statusCode) else {
                print ("server error")
                return
        }
        if let mimeType = response.mimeType,
            mimeType == "application/json",
            let data = data,
            let dataString = String(data: data, encoding: .utf8) {
            print ("got data: \(dataString)")
        }
    }
    task.resume()



}