collection-crud/src/Controller/DefaultController.php

<?php

namespace App\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Component\HttpFoundation\Request;

class DefaultController extends Controller
{
	/**
	 * @Route("/", name="homepage")
	 */
	public function indexAction(Request $request)
	{
		// replace this example code with whatever you need
		return $this->render('default/index.html.twig', [
			'base_dir' => realpath($this->getParameter('kernel.project_dir')) . DIRECTORY_SEPARATOR,
		]);
	}
}