Authorization in Datalife through social networks - how to parse data?

Question

PHP

SW. guru!
Does anyone understand how the authorization in Datalife takes place through social networks?
I would like to understand how to make sure that during authorization, information about a person is parsed, not only the name and email, but also gender, age, city and a link to a page on a social network.
Here is an example of a request that a site sends to a contact:
oauth.vk.com/authorize?client_id=4962742&redirect_...