laravel 5.7中的多重身份验证

Question

我是Laravel的新手，并使用Laravel5.7，因为我想对用户使用多种身份验证并使用单独的管理模型。当我提供用户名和密码时，它会重定向到登录页面本身。请指导我进行成功登录  路径为http://127.0.0.1:8000/admin/login

我的LoginController（app / Http / Controllers / Admin / HomeController.php）

<?php

namespace App\Http\Controllers\Admin\Auth;

use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\AuthenticatesUsers;
use Illuminate\Http\Request;

class LoginController extends Controller
{    
    use AuthenticatesUsers;    
    protected $redirectTo = '/admin/home';   
    public function __construct()
    {
        $this->middleware('guest:admin')->except('logout');
    }
    public function showLoginForm()
    {
        return view('admin.auth.login');
    }
    public function guard()
    {
        return \Auth::guard('admin');
    }
    public function logout(Request $request)
    {
        $this->guard('admin')->logout();
        return redirect('/');
    }
}

auth.php

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

        'admin' => [
            'driver' => 'session',
            'provider' => 'intis_admins'
        ],
'providers' => [
        'users' => [
            'driver' => 'eloquent',
            'model' => App\User::class,
        ],
        'intis_admins' => [
           'driver' => 'eloquent',
            'model' => App\Admin::class,
            ],

Handler.php

if(in_array('admin',$exception->guards())){
return redirect()->guest('admin/login');
 } 

web.php（/routes/web.php）

Route::group(['namespace' => 'Admin','prefix'=>'admin'],function(){
    Route::get('/',function(){
        return redirect()->to('admin/home');
    })->name('admin');
    // home
    Route::get('home','HomeController@index')->name('admin.home');
    // login logout
    Route::get('login','Auth\LoginController@showLoginForm')->name('admin.login');
    Route::post('login','Auth\LoginController@login')->name('admin.login');
    Route::post('logout','Auth\LoginController@logout')->name('admin.logout');

login.blade.php（views / admin / login.blade.php）

<form id="sign_in_adm" class="form-vertical" method="POST" action="{{ route('admin.login') }}">
            @csrf           
                <div class="control-group{{ $errors->has('username') ? ' has-error' : '' }}">
                    <div class="controls">
                        <div class="main_input_box">
                            <span class="add-on bg_lg"><i class="icon-user"> </i></span>
                            <input id="username" type="text" class="form-control{{ $errors->has('username') ? ' is-invalid' : '' }}" name="username" value="{{ old('username') }}" required autofocus>
                            <!--<input type="text" placeholder="Username" name="username" />-->
                            @if ($errors->has('username'))
                            <span class="text-danger"><strong>{{ $errors->first('username') }}</strong></span>
                            @endif
                        </div>
                    </div>
                </div>
                <div class="control-group{{ $errors->has('password') ? ' has-error' : '' }}">
                    <div class="controls">
                        <div class="main_input_box">
                            <span class="add-on bg_ly"><i class="icon-lock"></i></span>                               
                            <input id="password" type="password" class="form-control{{ $errors->has('password') ? ' is-invalid' : '' }}" name="password" required>
                            <!--<input type="password" name="password" placeholder="Password" />-->
                            @if ($errors->has('password'))
                                <span class="help-block">
                                    <strong>{{ $errors->first('password') }}</strong>
                                </span>
                            @endif
                        </div>
                    </div>
                </div>
                <div class="form-actions">
                <input class="filled-in chk-col-pink" type="checkbox" name="remember" id="remember" {{ old('remember') ? 'checked' : '' }}>
                        <label for="rememberme">Remember Me</label>
                    <span class="pull-left"><a href="#" class="flip-link btn btn-info" id="to-recover">Lost password?</a></span>
                    <span class="pull-right"><input type="submit" value="Login" href="index.html" class="btn btn-success" /> </span>
                </div>
            </form>

当我提供用户名和密码时，它会重定向到登录页面本身。请指导我进行成功登录