Document User Credentials setup for Authorisation of a new user

[elliotrock]

I have a iOS native app that I am trying to implement the full cycle of user's authorisation. That is:

1. First Authorisation using a username and password via an authorise.php
2. Returned token via token.php
3. redirect.php , I thought step 1 was enough to grant a users, how is this used in a native user and password setup?

The User Credentials documentation doesn't show what code is setup in what file.