Why I get "Forbidden. Need user." error?

The error means that in order to perform any actions you need to login and act on user behalf.

You can use one of the following:

iOS
[QBUsers logInWithUserLogin:@"igorigor" password:@"igorigor" delegate:self];
Or
[QBUsers logInWithUserEmail:@"qbuserqqqq34r5@gmail.com" password:@"qbuserr345" delegate:self];

Android
final QBUser user = new QBUser("testuser", "testpassword"); QBUsers.signIn(user, new QBCallbackImpl() { @Override public void onComplete(Result result) { if (result.isSuccess()) { QBUserResult qbUserResult = (QBUserResult) result; } else { handleErrors(result); } } });