access/application/index/controller/order.php

<?php

namespace app\index\controller;

class order extends base
{
    public function check_rcode()
    {
        $order_sn = input('param.order_sn');
        $url = base::admin_url . base::path_check_order;
        $resp = http_get($url,['order_sn' => $order_sn]);

        echo $resp;
    }
}