Dears, I've been following this tutorial to create a chatbot,by using Facebook Messenger: https://chatbotnewsdaily.com/build-a-facebook-messenger-chat-bot-in-10-minutes-5f28fe0312cd
I've completed all and I'm just about to deploy the webhook. The only problem is that on the step 4:(create our WebHook), click “Setup Webhooks”. I got 2 different messages on the Callback Url (red x), one was that the url returns “Hello World (from Flask!)”, instead of a numerical value that the system expects. The last message was now that the http Error 403. Any hints?
It seems like there is a problem with security - shall part of this code be changed to make it work/accepted by Facebook authentication?
The code is embedded in the page link.