How to integrate Facebook leads to Mautic?

I did a clean installation with Mautic with XAMPP locally and I downloaded a webhook from guithub to make the connection with facebook. link

I am using NGROK to create an HTTPS tunnel and take the tests online ... I configure the app on facebook as indicated by the tutorial within github, I create the app on facebook and I pass the 4 parameters in the Open Graph of face (object, fields, verify_token, callback url) but when I send it, I boot this error:

{
"error": {
"message": "(#2201) response does not match challenge, expected value=\"731589449\", received=\"731589449\u003Cbr \/>\n\u003Cb...\"",
"type": "OAuthException",
"code": 2201,
"fbtrace_id": "CyN9qwFaBdf"
  }
}