Authentication with Dropbox Api V2

I have been looking for several days and still don't know how to do this. Maybe you can help me.

I want to integrate Dropbox into my app and use the Dropbox API V2 . But the way to authenticate the application with the user's Acc is not described. To use the API, I am using the Maven dependency.

There is an example for android , but there is nothing about authentication. Is anyone who has done this already? But with V2, because V1 is deprecated.