Callback URL error when setting up webhook for messenger
<p>I'm trying to follow this <a href="https://blog.hartleybrody.com/fb-messenger-bot/" rel="nofollow">tutorial</a> to set a chatbot for messenger. I'm stuck on the webhook setup. I added the page token and verify token to heroku, but when I try to add the heroku URL as the callback URL I get </p>

<blockquote>
  <p>The URL couldn't be validated. Callback verification failed with the
  following errors: HTTP Status Code = 403; HTTP Message = FORBIDDEN</p>
</blockquote>

<p>The problem was the <code>PAGE_ACCESS_TOKEN</code> and <code>VERIFY_TOKEN</code> were not set. The tutorial said to use the command <code>heroku config:add</code> the correct command should be <code>heroku config:set</code>. </p>

python facebook bots