1. https://github.com/dcloudio/H5P.Server/tree/master/payment 使用sdk
2. 对接代码

    require_once "../payment/wxpayv3/WxPay.Api.php";
    require_once "../payment/wxpayv3/WxPay.Data.php";
    
    $unifiedOrder = new WxPayUnifiedOrder();
    $unifiedOrder->SetBody($subject);//商品或支付单简要描述
    $unifiedOrder->SetOut_trade_no($out_trade_no);
    $unifiedOrder->SetTotal_fee($total);
    $unifiedOrder->SetTrade_type("APP");
    $result = WxPayApi::unifiedOrder($unifiedOrder);