Authentication redirect route

can you help me how to create if isadmin is true it will be redirected to admin page, else home page.

AuthController

public function postLogin(Request $request){
       if(!auth()->attempt(['email' => $request->email, 'password' => $request->password])){
        return redirect()->back();
       }
       return redirect()->route('home');
    }

the main reason's maybe because this

return redirect()->route('home');

when tried change to ('admin') it successfully redirecting.

when i tried to add

protected function authenticated(\Illuminate\Http\Request $request, $user)
    {
        if( $user->isadmin){
           return redirect('admin');
        }
        return redirect('home');
    }

it didnt works too

via Chebli Mohamed