Website/app/config/packages/framework.php

<?php

use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
use Symfony\Config\FrameworkConfig;

return static function (FrameworkConfig $framework, ContainerConfigurator $container): void {

    $framework->secret('%env(APP_SECRET)%');
    $framework->httpMethodOverride(false);
    $framework->handleAllThrowables(true);

    $framework->session()
        ->handlerId(null)
        ->cookieSecure("auto")
        ->cookieSamesite("lax")
        ->storageFactoryId("session.storage.factory.native");

    $framework->phpErrors(["log" => true]);

    if ($container->env() === "test") {
        $framework->test(true);
        $framework->session()->storageFactoryId("session.storage.factory.mock_file");
    }

    if ($container->env() === "prod") {
        $framework->session()->handlerId('file://%kernel.project_dir%/var/sessions');
    }
};