cakePHP registration don't work - php

Question

I'm new to CakePHP and just starting with the CookBook Examples. Now I want to create a simple registration and Login form with my custome Table columns. But the system do not want to insert the data! Where is my mistake? Is it right to tell him in the AppController which fields to use?
add.ctp=
<div class="users_form">
<?= $this->Form->create($user) ?>
<fieldset>
<legend><?= __('Add') ?></legend>
<?= $this->Form->input('username') ?>
<?= $this->Form->input('password') ?>
</fieldset>
<?= $this->Form->button(__('Submit')); ?>
<?= $this->Form->end() ?>
UsersTable.php
class UsersTable extends Table{
public function initialize(array $config)
{
parent::initialize($config);
$this->table('ab_login');
}
public function validationDefault(Validator $validator)
{
return $validator
->notEmpty('username', 'insert name')
->notEmpty('password', 'pw insert');
}
}
AppController.php
parent::initialize();
$this->loadComponent('RequestHandler');
$this->loadComponent('Flash');
$this->loadComponent('Auth', [
'authenticate' => [
'Form' => [
'fields' => ['username' => 'ab_mail', 'password' => 'ab_pass']
]
]
]);
UsersController.php
public function add()
{
$user = $this->Users->newEntity();
if ($this->request->is('post'))
{
$user = $this->Users->patchEntity($user, $this->request->data);
if ($this->Users->save($user))
{
$this->Flash->success(__('inserted!'));
return $this->redirect(['action' => 'add']);
}
$this->Flash->error(__('Error!'));
}
$this->set('user', $user);
}

Answer 1

Change the form elements in your view to:
<?= $this->Form->input('ab_mail') ?>
<?= $this->Form->input('ab_pass') ?>

Answer 2

Need to Change in AppController.php
parent::initialize();
$this->loadComponent('RequestHandler');
$this->loadComponent('Flash');
$this->loadComponent('Auth', [
'authenticate' => [
'Form' => [
'fields' => ['username' => 'username', 'password' => 'password'] // Password and Username fields are pre-define in cakephp.
]
]
]);
It will definitely work.
thanks :)