Warning: Undefined variable $router in C:\xampp\htdocs\astra-backoffice\vendor\laravel\framework\tests\Routing\fixtures\routes.php on line 3

Fatal error: Uncaught Error: Call to a member function get() on null in C:\xampp\htdocs\astra-backoffice\vendor\laravel\framework\tests\Routing\fixtures\routes.php:3 Stack trace: #0 {main} thrown in C:\xampp\htdocs\astra-backoffice\vendor\laravel\framework\tests\Routing\fixtures\routes.php on line 3