Laravel admin login with guard

Admin.php

<?php
//model
namespace App;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Foundation\Auth\User as Authenticatable;

class Admin extends Authenticatable

{
    //
}

auth.php

<?php
//Confiig

return [

    /*
    |--------------------------------------------------------------------------
    | Authentication Defaults
    |--------------------------------------------------------------------------
    |
    | This option controls the default authentication "guard" and password
    | reset options for your application. You may change these defaults
    | as required, but they're a perfect start for most applications.
    |
    */

    'defaults' => [
        'guard' => 'web',
        'passwords' => 'users',
    ],

    /*
    |--------------------------------------------------------------------------
    | Authentication Guards
    |--------------------------------------------------------------------------
    |
    | Next, you may define every authentication guard for your application.
    | Of course, a great default configuration has been defined for you
    | here which uses session storage and the Eloquent user provider.
    |
    | All authentication drivers have a user provider. This defines how the
    | users are actually retrieved out of your database or other storage
    | mechanisms used by this application to persist your user's data.
    |
    | Supported: "session", "token"
    |
    */

    'guards' => [
        'web' => [
            'driver' => 'session',
            'provider' => 'users',
        ],

        'api' => [
            'driver' => 'token',
            'provider' => 'users',
        ],

        'admin' => [
            'driver' => 'session',
            'provider' => 'admins',
        ],
    ],

    /*
    |--------------------------------------------------------------------------
    | User Providers
    |--------------------------------------------------------------------------
    |
    | All authentication drivers have a user provider. This defines how the
    | users are actually retrieved out of your database or other storage
    | mechanisms used by this application to persist your user's data.
    |
    | If you have multiple user tables or models you may configure multiple
    | sources which represent each model / table. These sources may then
    | be assigned to any extra authentication guards you have defined.
    |
    | Supported: "database", "eloquent"
    |
    */

    'providers' => [
        'users' => [
            'driver' => 'eloquent',
            'model' => App\User::class,
        ],
        'admins' => [
            'driver' => 'eloquent',
            'model' => App\Admin::class,
        ],

        // 'users' => [
        //     'driver' => 'database',
        //     'table' => 'users',
        // ],
    ],

    /*
    |--------------------------------------------------------------------------
    | Resetting Passwords
    |--------------------------------------------------------------------------
    |
    | You may specify multiple password reset configurations if you have more
    | than one user table or model in the application and you want to have
    | separate password reset settings based on the specific user types.
    |
    | The expire time is the number of minutes that the reset token should be
    | considered valid. This security feature keeps tokens short-lived so
    | they have less time to be guessed. You may change this as needed.
    |
    */

    'passwords' => [
        'users' => [
            'provider' => 'users',
            'table' => 'password_resets',
            'expire' => 60,
        ],
        'admins' => [
            'provider' => 'admins',
            'table' => 'password_resets',
            'expire' => 60,
        ],
    ],

];

AuthController.php

<?php
// Admin controller
namespace App\Http\Controllers\Hq;

use Illuminate\Contracts\Validation\Validator;
use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\Auth;
use App\Admin;
use Illuminate\Support\Facades\Hash;

class AuthController extends Controller
{
    protected $guard = 'admin';

    protected $redirectTo = '/hq';

    protected $loginPath = '/hq/login';

    public function __construct()
    {
        $this->redirectTo = '/hq';
    }

    protected function validator(array $data)
    {
        return Validator::make($data, [
            'name' => 'required|max:255',
            'email' => 'required|email|max:255|unique:admins',
            'password' => 'required|min:6|confirmed',
        ]);
    }

    public function logout()
    {
        Auth::guard('admin')->logout();
        return redirect('/');
    }

    public function login(Request $request)
    {

        $this->validate($request, [
            'email' => 'required',
            'password' => 'required',
        ]);

        $admin = Admin::where('email', $request->email)->first();

        if (!$admin) {
            return redirect($this->loginPath)->with('error', 'Admin bulunamadi.');
        }

        if (Hash::check($request->password, $admin->password)) {
            Auth::guard('admin')->login($admin);
            return redirect('/hq');
        }

        return redirect($this->loginPath)
            ->withInput($request->only('email', 'remember'))
            ->withErrors(['email' => 'Incorrect email address or password']);
    }

    public function showLoginForm()
    {
        if (Auth::guard('admin')->check()) {
            return redirect('/hq');
        }

        return view('hq.auth.login');
    }
}