// config/bootstrap.php

Plugin::load('DejwCake/AdminLTE', ['bootstrap' => true, 'routes' => true]);

// src/Controller/AppController.php

public function beforeRender(Event $event)
{
    $this->viewBuilder()->setTheme('DejwCake/AdminLTE');
}

// src/View/AppView.php

public function initialize()
{
    $this->loadHelper('Form', ['className' => 'DejwCake/AdminLTE.Form']);
}

// src/Controller/AppController.php
use Cake\Core\Configure;

public function beforeRender(Event $event)
{
    // ...
    $this->set('theme', Configure::read('Theme'));
}

// To customize configuration paste it at end of file config/bootstrap.php

Configure::write('Theme.title', 'CMS');
Configure::write('Theme.logo', [
    'mini' => 'CMS',
    'large' => 'CMS'
]);