title: post message to slack using API
body: <p>I'm trying to post a message to Slack using their API and the response says: <code>Waiting for activation</code></p>
  
  <p>This is my code:</p>
  
  <pre><code>static async Task&lt;HttpResponseMessage&gt; PostMessage()
  { 
      client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", "xoxb-924542226483-938230541718-gk3vTmwEtOOK01NqO5kW6e0R");
      var atttrJson = new stackAttributes { channel = "#cymulateinterview", text = "Good Morning all" };
      var json = new JavaScriptSerializer().Serialize(atttrJson);
      var buffer = System.Text.Encoding.UTF8.GetBytes(json);
      var byteContent = new ByteArrayContent(buffer);
      byteContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
      var result = await client.PostAsync("https://slack.com/api/chat.postMessage", byteContent);
      return result;
  }
  </code></pre>
  
  <p>What am I missing </p>