Call Facebook graph API from backend after user connected through mobile app

i need few advice on my newbie frenchy project...

How can I call the Facebook graph api directly from a backend (python and bottle) after the user simply gave his authorization on the mobile app (Ionic framework) ?

I had in mind to send the Facebook token received on mobile app to the backend and use it to access information directly.

Also does anyone know if there is a best practice to get user Facebook information (profile basic info and friends list) on a backend ?

I know my question is very broad, but i'm just looking for a clue to know which way to go

Thank you