Codeigniter Shield how to redirect seperate URL if the user not in group?

I’m trying to restrict users to access the administration area using Shield package Authorization group. everything works fine but it redirects to index page if the user not in group.

How i can redirect them to seperate page instead of redirecting to the index page ?

My code looks like :

$routes->group("admin", ["namespace" => "AdminControllers", "filter" => "group:admin"], static function ($routes) {
 
 
 
    $routes->get('entities', 'Entities::index');
    $routes->post('entities/create', 'Entities::create');
 
});