title: What is Callback URL in Facebook webhook page subscription?
body: <p>I'm trying to stream the real time public feeds using Facebook Web-hook API. Here I'm trying to set up a page subscription in Web-hook console. There is a field called Callback URL. What is this URL about?</p>
  
  <p>I have also tried going through the documentation for  Setting up callback URL. but I Couldn't figure out. </p>
  
  <p><a href="https://developers.facebook.com/docs/graph-api/webhooks#setup" rel="noreferrer">https://developers.facebook.com/docs/graph-api/webhooks#setup</a></p>
  
  <p>Cant the callback URL be SSL localhost? Whenever I try to give a localhost URL i get a error message "Unable to verify provided URL". </p>