When authenticating to V3, I'm using
And I get the following screen on Android: https://i.imgur.com/3X1MpCC.png
However, using V4, the URL will be
And the screen that I get is: https://i.imgur.com/BVVYIU4.png
With V3, it is not required to be signed in - the user gets the Login and Signup options and the token is not lost after either action. However, for V4 the user gets an 'error' message, and when he chooses to sign in or sign up, the token is lost.
I can't access the /authenticate/ route for V4, it seems to only work with V3 tokens. With the V3 system, the user only needs to go to TMDB once. With V4, I'll need to open TMDB once to log in and another for the user to allow my API key (approve his request token and ask for an access token).
Am I missing something or is it really necessary to do that for V4?
PS: I only want to have one auth system in my app, however I was having problems with V4 and decided to try V3. I will need V4's features in the future.
Thank you in advance, Luís