How to get user info after successfully login?

Dear bruno , thanks for you response.
You assumed well : Im building a regular web application.
I have been looking for some working php example about how to continue after getting the state and code tokens.
I dont know what to do with them , I need to exchange them for some util information in order to properly route and render the response.
If you can point some util example or reading documentation , i will apretiate it.
Regards.
Leandro.