Помогите разобраться - отправка картинки в Телеграм канал через API

return temp;

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.IO;
using System.Text.RegularExpressions;
using ZennoLab.CommandCenter;
using ZennoLab.InterfacesLibrary;
using ZennoLab.InterfacesLibrary.ProjectModel;
using ZennoLab.InterfacesLibrary.ProjectModel.Collections;
using ZennoLab.InterfacesLibrary.ProjectModel.Enums;
using ZennoLab.Macros;
using Global.ZennoExtensions;
using ZennoLab.Emulation;
using System.Net.Http;

namespace ZennoLab.OwnCode
{
    /// <summary>
    /// A simple class of the common code
    /// </summary>
    public class CommonCode
    {
        /// <summary>
        /// Lock this object to mark part of code for single thread execution
        /// </summary>
        public static object SyncObject = new object();

        // Insert your code here
        public static string SendPhoto (string photo, string url_telegram, string proxy)
        {
          var sBoundary = DateTime.Now.Ticks.ToString("x");
          var contentType = "multipart/form-data";
          string sPostMultiString = "";
          // функция сбора данных
          Func<string, string, string, string> multiFormDataText = delegate(string key, string value, string boundary)
            {
               var output = string.Format("--{0}\r\n", boundary);
               output += string.Format("Content-Disposition: form-data; name=\"{0}\"\r\n\r\n", key);
               output += value + "\r\n";
               return output;
            };
          // функция сбора данных
          Func<string, string, string, string, string, string> multiFormDataFile = delegate(string key, string value, string fileName, string fileType, string boundary)
            {
               var output = string.Format("--{0}\r\n", boundary);
               output += string.Format("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\n", key, fileName);
               output += string.Format("Content-Type: {0}\r\n\r\n", fileType);
               output += string.Format("{0}\r\n", value);
               return output;
            };
          // другие поля
          sPostMultiString += multiFormDataText("action", "upload", sBoundary);
          // файл
          string pro = proxy;
          var fileInfo = new System.IO.FileInfo(photo);
          sPostMultiString += multiFormDataText("width", fileInfo.Name, sBoundary);
          sPostMultiString += multiFormDataFile("photo", fileInfo.FullName, fileInfo.Name, "image/png", sBoundary);
          var str = ZennoPoster.HttpPost(url_telegram, sPostMultiString, contentType, pro, Cookies: "", AdditionalHeaders: new string[]{""});
          return str;
        }
    }
  
}

string strToken = project.Variables["bot_id"].Value;
string strChatId = project.Variables["chat_id"].Value;
string parse_mode = "html";
string proxy = project.Variables["proxy"].Value;
string img = project.Variables["img"].Value;
string url_bot = string.Format("https://api.telegram.org/{0}/sendPhoto?chat_id={1}", strToken, strChatId);
string temp = CommonCode.SendPhoto(img, url_bot, proxy);
return temp;

string strToken = project.Variables["bot_id"].Value;
string strChatId = project.Variables["chat_id"].Value;
string parse_mode = "html";
string img = project.Variables["img"].Value;
string url_bot = string.Format("https://api.telegram.org/{0}/sendPhoto?chat_id={1}", strToken, strChatId);
string temp = CommonCode.SendPhoto(img, url_bot);