title: facebook messenger handover protocol take_thread_control
body: <p>i created a bot with messenger and dialogflow, This works good<br>
  but the problem comes when i try to implement the handover protocol</p>
  
  <p><strong>First approach : <em>Pass thread control to PAGE INBOX</em></strong><br>
  i set up an intent on dialogflow with 'input.handover' action then when i type handover i call my webhook and make a call to fb api with pass_thread_control and i passe the control to the page inbox, i get a success response and the conversation pass from the <strong>BOT</strong> to <strong>PAGE INBOX</strong>. But here a stuck to <strong>PAGE INBOX</strong> and i cant take_thread_control to the <strong>BOT</strong> because the <strong>PAGE INBOX</strong> not linked with the dialogflow or any other webhook.  </p>
  
  <p><strong>Second approach : <em>Pass thread control to another app</em></strong><br>
  with the same setup of first approach but this time i pass the thread control to a facebook <strong>APP</strong> i created and linked with a webhook (with nodejs hosted on heroku), i get a success response but this time no message come to this <strong>APP</strong> inbox and on heroku console i can see the message come to webhook but not <strong>APP</strong> inbox.</p>
  
  <p>And now i just stuck here. if any one have an idea how to implement the handover protocol with dialogflow or any help, i appreciate that.</p>
  
  <p><strong>Thanks.</strong></p>