Custom Guard Authentication Exception - laravel

Question

I created a custom guard (admin) in my application, and everything looks good following this tutorial online (https://pusher.com/tutorials/multiple-authentication-guards-laravel). The only problem is when i try to access a view that is protected by the admin guard, instead of giving me a exception NotAuthenticate, is giving me a "InvalidArgumentException
Route [login] not defined.".
My Dashboard controller custom guard is:
public function __construct()
{
$this->middleware('auth:admin');
}
But the strange thing that i cant understand whats going on is that when i add in my web.php routes the "Auth::routes();", it works fine, the Exception NotAuthenticate gets fired.
Is there a reason why my custom only works has expected with i add the Auth::routes() ?
Admin Login Controller:
namespace App\Http\Controllers\Admin\Auth;
use Auth;
use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\AuthenticatesUsers;
use Illuminate\Validation\ValidationException;
class LoginController extends Controller
{
use AuthenticatesUsers;
/**
* Where to redirect users after login.
*
* #var string
*/
protected $redirectTo = '/admin/dashboard';
/**
* Create a new controller instance.
*
* #return void
*/
public function __construct()
{
$this->middleware('guest:admin')->except('logout');
}
public function login(Request $request)
{
$this->validateLogin($request);
// If the class is using the ThrottlesLogins trait, we can automatically throttle
// the login attempts for this application. We'll key this by the username and
// the IP address of the client making these requests into this application.
if ($this->hasTooManyLoginAttempts($request)) {
$this->fireLockoutEvent($request);
return $this->sendLockoutResponse($request);
}
if ($this->attemptLogin($request)) {
return $this->sendLoginResponse($request);
}
// If the login attempt was unsuccessful we will increment the number of attempts
// to login and redirect the user back to the login form. Of course, when this
// user surpasses their maximum number of attempts they will get locked out.
$this->incrementLoginAttempts($request);
return $this->sendFailedLoginResponse($request);
}
public function showLoginForm()
{
return view('admin.auth.login');
}
/**
* Log the user out of the application.
*
* #param \Illuminate\Http\Request $request
* #return \Illuminate\Http\Response
*/
public function logout(Request $request)
{
$this->guard()->logout();
$request->session()->invalidate();
return $this->loggedOut($request) ?: redirect('/admin');
}
/**
* Get the guard to be used during authentication.
*
* #return \Illuminate\Contracts\Auth\StatefulGuard
*/
protected function guard()
{
return Auth::guard('admin');
}
}

Answer 1

Try following the following tutorial, it did the trick for me.
On a side note: Avoid modifying the existing controller that laravel ships with, instead extend it and implement your own functionality. This practice will take you the long way.
https://www.codementor.io/okoroaforchukwuemeka/9-tips-to-set-up-multiple-authentication-in-laravel-ak3gtwjvt