How to properly implement UserActor?

Question

Java

Hello, who is able to explain to me how to implement the UserActor correctly, since I do not understand the documentation of this particular section. Here is the code given:

UserAuthResponse authResponse = vk.oAuth()
                .userAuthorizationCodeFlow(APP_ID, CLIENT_SECRET, REDIRECT_URI, code)
                .execute();
UserActor actor = new UserActor(authResponse.getUserId(), authResponse.getAccessToken());

I understood how to get APP_ID and CLIENT_SECRET, but I don’t understand how to get everything else. Explain step by step. After all, this is what websites are for.