ManageController.php

<?php

/*
#
#   ManageController.php
#
#   This file handle the backoffice management of the site.
#
#
*/

namespace App\Controller;

use App\Controller\AppController;
use Authorization\Policy\MapResolver;

class ManageController extends AppController{

    public function initialize(): void
    {
        parent::initialize();
        $this->loadModel('Users');
        $this->Authentication->allowUnauthenticated(['index', 'users']);
        $this->Authorization->authorize($this);
    }

    public function index()
    {
        //$this->Authorization->authorize($this, 'index');
        $this->viewBuilder()->setLayout('adminlayout');
        //$this->layout='adminlayout';
    }

    public function users()
    {
        //$session = $this->request->getSession();

        $resultset = $this->Users->find()->all();
        $this->set('userlist', $resultset);
    }

    public function updateuser(){

        if ($this->request->is('post')) {
             $user = $this->Users->get($this->request->getData('id'));

             $user->username = $this->request->getData('username');
             $user->firstname = $this->request->getData('firstname');
             $user->surname = $this->request->getData('surname');
             $user->email = $this->request->getData('email');
             $user->editedon = date("Y-m-d H:i:s");

             $this->Users->save($user);
             $this->Flash->success('User has been successfully updated.');
             return $this->redirect(
            ['controller' => 'manage', 'action' => 'users']
        );
        }else{
            $this->Flash->error('No POST data received.');
        }
    }

}