generate an access token from facebook graph api

 create an app

get the app id 

after open tthat app

u can see AppId:

and get client_secret using

settings ->advanced -> enable require app secret

save changes inthat client token 

it is used for api

generate access token 

https://graph.facebook.com/oauth/access_token?client_id=717723222201461&client_secret=401800f29180fb413ef7f22093f13341&grant_type=client_credentials