PHP怎么将公众号支付转换为WAP支付

<?php

require_once 'WxPayapi.php';

$input = new WxPayUnifiedOrder();
$input->SetBody("商品描述");
$input->SetAttach("附加数据");
$input->SetOut_trade_no("商户订单号");
$input->SetTotal_fee("订单总金额，以分为单位");
$input->SetTime_start(date("YmdHis"));
$input->SetTime_expire(date("YmdHis", time() + 600));
$input->SetGoods_tag("商品标记");
$input->SetNotify_url("回调地址");
$input->SetTrade_type("jsAPI");
$input->SetOpenid("用户openid");
$order = WxPayApi::unifiedOrder($input);

$url_params = [
    "appid" => "公众号appid",
    "mch_id" => "商户号",
    "nonce_str" => md5(time()),
    "prepay_id" => $order["prepay_id"],
    "time_stamp" => time(),
    "sign_type" => "MD5",
];

ksort($url_params, SORT_STRING);
$sign_str = '';
foreach ($url_params as $k => $v) {
    $sign_str .= "{$k}={$v}&";
}
$sign_str .= "key=商户支付密钥";  
$url_params["sign"] = md5($sign_str);

$url = sprintf("https://wx.tenpay.com/cgi-bin/mmpayWEB-bin/checkmweb?%s", Http_build_query($url_params));

header("Location: {$url}");
exit;