collection-crud/src/Controller/DefaultController.php

<?php declare(strict_types=1);

namespace App\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\{Request, Response};
use Symfony\Component\Routing\Annotation\Route;

class DefaultController extends AbstractController
{
    #[Route(path: '/', name: 'homepage')]
    public function indexAction(Request $request): Response
    {
        // 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,
        ]);
    }
}