title: Dialogflow fulfillment answers don't reach Telegram, Facebook and Slack integration
body: <p>I created a simple bot to test some new resources, but I'm facing an issue with <strong>fulfillment responses</strong> on some clients. I'm testing with many integrations.   </p>
  
  <ul>
  <li>✅ The <strong>fulfillment</strong> work fine with: Web Demo and Dialogflow Messenger</li>
  <li> The <strong>fulfillment</strong> fails with: Facebook Messenger, Slack and Telegram</li>
  </ul>
  
  <p>I wrote two intents to test:</p>
  
  <ol>
  <li>"Hello" - Text Response Intent</li>
  <li>"Hi" -  Fulfillment Intent answered by node using <code>actions-on-google</code> package.</li>
  </ol>
  
  <p>What happened:</p>
  
  <ul>
  <li>"Hello" - intent works on all integrations, like expected.</li>
  <li>"Hi" - intent works like expected with Dialogflow native integrations (✅ )</li>
  <li><p>"Hi" - intent doesn't work with other integrations (), but it shows "Typing..." while my node backend creates the answer, but the text response is never showed.</p></li>
  <li><p>In debug mode, I see that the request is received, the intent match, and the <code>Response</code> object are like expected.</p></li>
  </ul>
  
  <h3>Node code:</h3>
  
  <pre><code>const { dialogflow } = require('actions-on-google');
  const app = dialogflow({ debug: true });
  
  ... 
  
  app.intent('Hi', conv =&gt; {
    console.log('&gt;&gt; Hi Fulfillment reached');
    conv.ask(`Hi! I'm a fulfillment response on node!`);
  });
  </code></pre>
  
  <h3>Node response (console output):</h3>
  
  <pre><code>&gt;&gt; Hi Fulfillment reached
  Response {
    "status": 200,
    "headers": {
      "content-type": "application/json;charset=utf-8"
    },
    "body": {
      "payload": {
        "google": {
          "expectUserResponse": false,
          "richResponse": {
            "items": [
              {
                "simpleResponse": {
                  "textToSpeech": "Hi! I'm a fulfillment response on node!"
                }
              }
            ]
          }
        }
      }
    }
  }
  POST /api/chatBot/ 200 156 - 1419.611 ms
  </code></pre>
  
  <p>I recorded my screen to show better that behavior.</p>
  
  <p><a href="https://i.stack.imgur.com/mLNhJ.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mLNhJ.gif" alt="enter image description here"></a></p>
  
  <p>Any help is appreciated!</p>