UrlSession Timed out error received after POST request

I tried to Send a POST request to a website by using urlsession task and i can never get a response back after. What i can get is a error message which shows:

error=Optional(Error Domain=NSURLErrorDomain Code=-1001 "The request timed out." UserInfo={NSErrorFailingURLStringKey=https://mss.cpc.getswish.net/swish-cpcapi/api/v1/paymentrequests/, NSErrorFailingURLKey=https://mss.cpc.getswish.net/swish-cpcapi/api/v1/paymentrequests/, _kCFStreamErrorDomainKey=4, _kCFStreamErrorCodeKey=-2103, NSLocalizedDescription=The request timed out.})

2018-10-11 13:35:47.594310+0200 SwishFinalTestingIOS[5264:2203153] Task <B7405BAC-9E65-4DAA-A8C6-BA5D826386D4>.<1> finished with error - code: -999

2018-10-11 13:35:47.595138+0200 SwishFinalTestingIOS[5264:2203154] Task <B7405BAC-9E65-4DAA-A8C6-BA5D826386D4>.<1> HTTP load failed (error code: -999 [1:89])

I followed this guide in stackoverflow: https://stackoverflow.com/questions/44564422/request-timed-out-with-code

but it dosen't help me to solve my problem.

i tried to extend the timeout interval to 120 but i still can't load the data.

When i run my code, i will stuck at session.dataTask(with: request) and then my request time running out.

my Info.plist:

<key>NSAppTransportSecurity</key>
    <dict>
        <key>NSAllowsArbitraryLoads</key>
        <true/>
        <key>NSExceptionDomains</key>
        <dict>
            <key>mss.cpc.getswish.net</key>
            <dict>
                <key>NSExceptionAllowsInsecureHTTPLoads</key>
                <true/>
                <key>NSIncludesSubdomains</key>
                <true/>
            </dict>
        </dict>
    </dict>
</dict>

my post request code:

let url = URL(string: "https://mss.cpc.getswish.net/swish-cpcapi/api/v1/paymentrequests/")!
        let params = [
            "payeePaymentReference": "0123456789",
            "callbackUrl": "https://example.com/api/swishcb/paymentrequests",
            "payeeAlias": "1231181189",
            "amount": "100",
            "currency": "SEK",
            "message": "Kingston USB Flash Drive 8 GB"
        ]
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        var headers = request.allHTTPHeaderFields ?? [:]
        headers["Content-Type"] = "application/json"
        request.allHTTPHeaderFields = headers
        guard let httpBody = try? JSONSerialization.data(withJSONObject: params, options: []) else {
            return
        }
        request.httpBody = httpBody
        print("jsonData: ", String(data: request.httpBody!, encoding: .utf8) ?? "no body data")
        // Create and run a URLSession data task with our JSON encoded POST request
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForResource = 120
        config.timeoutIntervalForRequest = 120
        let session = URLSession(configuration: config, delegate: self, delegateQueue: OperationQueue.current)
        let task = session.dataTask(with: request) { (data, response, error) in
            guard error == nil && data != nil else {
                print("error=\(String(describing: error))")
                return
            }
            if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode != 200 {
                print("statusCode should be 200, but is \(httpStatus.statusCode)")
                print("response = \(String(describing: response))")
                return
            }
            let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)!
            let responseStringForJson = "[\(responseString)]"
            print("result = \(String(describing: responseStringForJson))")
        }
        task.resume()

This is the format for sending the POST request code:

https://imgur.com/a/dpIX087