How to generate a Facebook "never" expire Access Token
Suppose you already have generated a long-lived access token whose expiration date is set to 60 days and you want to extend that token to never expire. All you need to do is make a “GET” request to the following endpoint:
https://graph.facebook.com/v2.6/me/accounts?fields=access_token&access_token=YOUR_ACCESS_TOKEN_HERE. [Don’t forget to set your long-lived access token and Facebook’s API version accordingly] You can now check your access token using Facebook’s debugger tool and you should have a Facebook Access Token that doesn’t expire.