This call below can get the leads data.
https://graph.facebook.com/v3.2/478694035993038/leads?access_token=
and it’s the form id : 478694035993038
But the main problem will be that it will only have 1 hour to expire.
Go to the link below
https://developers.facebook.com/tools/accesstoken
It will show all access token information.
Click on debug after the user access token , on the new page at the bottom you will see there is a button to extend the token expiry, click on it then it will have 2 months of expiry.
