Localde Calısırken Hiç bir Sorun almıuyorum olmasıg erektıgı gibi çalışıyor anca sunucuya atınca istek gitmıyor nedenini anlayamadım
"Object reference not set to an instance of an object." diyor sunucuda istek sanki karşıya hiç gitmıyor

try
            {
                Guid guid = Guid.NewGuid();
                string str = guid.ToString();

                var client = new RestClient("https://xxxx.com/checkout/transaction");
                var request = new RestRequest(Method.POST);
                request.AddHeader("postman-token", "ee0b9931-f610-62b2-a534-6d3149bad2fd");
                request.AddHeader("cache-control", "no-cache");
                request.AddHeader("x-merchant-api-key", "cd309c7290fxxxxxxxxx9accd7e7e340");
                request.AddHeader("accept", "application/json");
                request.AddHeader("content-type", "application/json");
                request.AddParameter("application/json", "{\n\t\"merchantId\": \"9501f8xxxxxxxxxxx7e44f6\",\n\t\"amount\" : " + TextBox1.Text + ",\n\t\"currency\": \"TRY\",\n\t\"successUrl\": \"http://sssss.com/Durum.aspx?Durum=ONAY\",\n\t\"failureUrl\": \"http://ssssscom/Durum.aspx?Durum=RED\",\n\t\"externalTransactionId\":\"" + str + "\",\n\t\"email\":\"x@x.com\"\n}", ParameterType.RequestBody);
                
                IRestResponse response = client.Execute(request);

                Response.Write("CEVAP: "+response.Content.ToString());


                RootObject googleResults = new RootObject();
                googleResults = JsonConvert.DeserializeObject<RootObject>(response.Content.ToString());

                Response.Redirect(googleResults.data.paymentUrl);
            }
            catch (Exception ex)
            {

                Response.Write(ex.Message);
            }