Laravel Facebook登录：错误app_id是必需的

Question

我正在使用laravel 5.1，我想将facebook社交登录添加到我的页面，但它返回错误

The parameter app_id is required

routes.php文件

Route::get('/redirect', 'UserController@redirect');
Route::get('/callback', 'UserController@callback');

UserController中

public function redirect(){
    return Socialite::driver('facebook')->redirect();
}

Composer.json

"require": {
    "php": ">=5.5.9",
    "laravel/framework": "5.1.*",
     "laravel/socialite": "^2.0",
}

配置/ Services.php

'facebook' => [
    'client_id' => '222221956976734',
    'client_secret' => 'a5acf8e8e01745d47rer829a0094vfvf',
    'redirect' => 'http://localhost/myproject/public/callback',
],

HTML

<a href="{{ URL::to('/redirect') }}" style="background-color : rgb(59,89,152)" class="btn blue_btn_big">Login via Facebook</a>

我在这里错过了...非常感谢任何帮助..