A plugin by the name "getServiceLocator" was not found in the plugin manager Zend Mvc Controller Pluginmanager

Question

I recently started learning Zend Framework2 from Angularjs through a course from the School of Net. Considering the year of the course, which if I’m not mistaken is 2013, some things have changed in both frameworks. Soon, I encountered a problem using the following code snippet to test the connection to the database and list the records using Doctrine 2:

namespace Application\Controller;

use Zend\Mvc\Controller\AbstractActionController;
use Zend\View\Model\ViewModel;

class IndexController extends AbstractActionController {
    public function indexAction() {
        $em = $this->getServiceLocator()->get('Doctrine\ORM\EntityManager');
        $repo = $em->getRepository('Entity\Categoria');

        $categorias = $repo->findAll();

        return new ViewModel(['categories'=>$categorias]);
    }
}

When I run the application, returns the following error:

A plugin by the name "getServiceLocator" was not found in the plugin manager Zend Mvc Controller Pluginmanager

In addition, additional information:

Zend Servicemanager Exception Servicenotfoundexception

And the archive where, apparently, the message comes from:

C: xampp htdocs ZF2 vendor course zendframework zend-servicemanager src Abstractpluginmanager.php:133

As far as I know, the problem stems from the fact that the method getServiceLocator() was taken from the most recent versions of Zend Framework 2. However, I have no idea how to solve it so that I can continue my tests and pass the course. Someone can give me a light?