Вопрос по загрузке фото на фотохостинг imgbb.com get/post методом

var key = project.Variables["key"].Value;
var image = project.Variables["Base64"].Value;
string data = string.Empty;
data += "--8d769bc76365cd4\n";
 resRequest = new[] {ZennoPoster.HttpPost("https://api.imgbb.com/1/upload?key=" + key + "&image=" + image +",     
    data,
    "multipart/form-data",
    "",
    "UTF-8",
    ZennoLab.InterfacesLibrary.Enums.Http.ResponceType.HeaderAndBody,
    30000,
    "",
    "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0",
    true,
    5,}
    new[] {"Host: api.imgbb.com"} );

using System.Net.Http;
using System.Net.Http.Headers;

string path = @"C:\Users\User\Desktop\картинка.jpg"; // Путь к картинке
string url = @"https://imgbb.com";
var auth_token = Regex.Match(ZennoPoster.HttpGet(url), @"(?<=PF\.obj\.config\.auth_token="").*?(?="";)").Value;

var sBoundary = DateTime.Now.Ticks.ToString("x");
var content = new MultipartFormDataContent(sBoundary);
    content.Add(new StreamContent(File.OpenRead(path)), name: "source", fileName: Path.GetFileName(path));
    content.Add(new StringContent("file"), "type");
    content.Add(new StringContent("upload"), "action");
    content.Add(new StringContent(string.Format(@"{0}",(int)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds)), "timestamp");
    content.Add(new StringContent("P6D"), "expiration");
    content.Add(new StringContent(auth_token), "auth_token");
    //string proxy = "127.0.0.1:8888";
string response = ZennoPoster.HTTP.Request(
    method: ZennoLab.InterfacesLibrary.Enums.Http.HttpMethod.POST,
    url: url+"/json",
    content: content.ReadAsByteArrayAsync().Result, 
    contentPostingType: string.Format("multipart/form-data;boundary={0}", sBoundary),
   // proxy: proxy,
    Encoding: "UTF-8",
    respType:ZennoLab.InterfacesLibrary.Enums.Http.ResponceType.BodyOnly,
    Timeout: 30000,
    Cookies: string.Empty,
   // UserAgent: UserAgent,
    AdditionalHeaders: new string[0],
    UseOriginalUrl: true,
    throwExceptionOnError: true,
    removeDefaultHeaders: true
  );
    
project.Json.FromString(response);
return project.Json.image.url;

content.Add(new StringContent("P6D"), "expiration");