screen/application/redirect/controller/Index.php

<?php

namespace app\redirect\controller;

use app\common\controller\Frontend;
use think\Cache;
use Yansongda\Supports\Str;

class Index extends Frontend
{

    protected $noNeedLogin = '*';
    protected $noNeedRight = '*';
    public function index()
    {
        $key=input('key');
        $html=Cache::get($key);
        if(!Str::startsWith($key,'payment_')||!$html){
            $this->redirect('/');
        }
        return $html;
    }
}