myProject/application/extra/system.php

<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2016 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

return [
    'mobile_key'=>'aladfa5a4g46jh4vb44n4e4r4t',//fuyou,alipay
    'pc_key'=>'aladfa5a4g46jh4vb44n4e4r4t',//fuyou,alipay
    'wap_key'=>'aladfa5a4g46jh4vb44n4e4r4t',//fuyou,alipay
];