Facebook for devloper glitch url call back

To link your bot to your Facebook page you need to add your Page Token, Verify Token and App Secret to the .env file of your Glitch project. The following steps tell you how to get each one:

Go to your app page on the Facebook for developers site and select Messenger from products on the left hand side.

Scroll down to Token Generation and select the page you created for your bot from the drop-down. This will generate your Page Access Token.

Add this to your .env file in your remixed Glitch project

Select Dashboard on your app page

Select Show App Secret and enter your Facebook password

Add your app secret to your .env file

Your Verify Token can be any string value you like, and is used to verify the connection between Facebook and your bot. In our code we are using ‘z-dev-demo’

Add your chosen Verify Token to your .env file

for better understanding go to 

https://medium.com/@alexcarltonsmith/build-a-facebook-bot-in-glitch-c39ca1609a9b