ysh/server/app/admin/controller/Index.php

<?php
// +----------------------------------------------------------------------
// | A3Mall
// +----------------------------------------------------------------------
// | Copyright (c) 2020 http://www.a3-mall.com All rights reserved.
// +----------------------------------------------------------------------
// | Author: xzncit <158373108@qq.com>
// +----------------------------------------------------------------------
namespace app\admin\controller;

use think\App;

class Index extends Auth {

    public function index(){
        return redirect(createUrl('platform.index/index'));
    }

}