RegistrationController.php

<?php

namespace App\Controller;
use Cake\Event\Event;
use Cake\ORM\TableRegistry;
use Cake\Utility\Hash;

class RegistrationController extends AppController
{

    public function beforeFilter(Event $event)
    {
        parent::beforeFilter($event);
        $this->Auth->allow(['index']);
    }

    public function test()
    {
        $entry = TableRegistry::get('EventCategoryParticipantEntries')->newEntity();

        $entry->errors('emy_contact_no.code', 'test');

        $this->set(compact('entry'));
    }
}