Erro rota plans.index

ola, estou usando o laravel 8 e ao executar a rota de plans da o erro abaixo:

Symfony\Component\Routing\Exception\RouteNotFoundException

Route [admin.index] not defined. (View: C:\xampp\htdocs\foods\resources\views\admin\pages\plans\index.blade.php)

class PlanController extends Controller

{

    public function index()

    {

    return view('admin.pages.plans.index');

    }

}