EntityTestRoutes.php

<?php

namespace Drupal\entity_test\Routing;

use Symfony\Component\Routing\Route;

/**
 * Subscriber for Entity Test routes.
 */
class EntityTestRoutes {
    
    /**
     * Returns an array of route objects.
     *
     * @return \Symfony\Component\Routing\Route[]
     *   An array of route objects.
     */
    public function routes() {
        $types = entity_test_entity_types(ENTITY_TEST_TYPES_ROUTING);
        $routes = [];
        foreach ($types as $entity_type_id) {
            $routes["entity.{$entity_type_id}.admin_form"] = new Route("{$entity_type_id}/structure/{bundle}", [
                '_controller' => '\\Drupal\\entity_test\\Controller\\EntityTestController::testAdmin',
            ], [
                '_permission' => 'administer entity_test content',
            ], [
                '_admin_route' => TRUE,
            ]);
        }
        return $routes;
    }

}