i am trying to use constructor in controller but failed !Why my constructor not working?

After user login you are redirecting the users to a route and that route points to a function, so basically you can implement this with a middleware or a simple function of redirect instead of constructor which is to initialize an object's properties.

 public function redirect()
    {
        $role = Auth::user()->role;
        return match ($role) {
            'Admin' => redirect('/admin/dashboard'),
            'Operator' => redirect('/operator'),
        };
    }

It's not possible by design. If you need it you can create middleware in constructor like this:

public function __construct()
{
    $this->middleware(function ($request, $next) {
        if (Auth::check()){
           if(Auth::user()->user_type == 'admin'){
              return to_route('admin.dashboard');
           } elseif(Auth::user()->user_type == 'operator'){
              return to_route('operator.dashboard');
           }
         }
 
         return $next($request);
    });
}

but you can also create normal middleware and use it for controller.

See this Laravel change to get more explanation