c#提交请求调用API

  string url = "https://cloud.soei.com.cn/smsapi/sms/verifycode";

    
         HttpClient httpClient = new HttpClient();
    
         httpClient.BaseAddress = new Uri(url);
    
         //表头参数
    
         string token = "9c0025b4aae442bda5498971ec1ab219";
    
         httpClient.DefaultRequestHeaders.Add("token", token);
    
         httpClient.DefaultRequestHeaders.Accept.Clear();
    
         httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
    
         try
    
         {
    
             using (var request = new HttpReques