代码开发H5纯签约接口，按照开发文档编辑参数，

https://api.mch.weixin.qq.com/papay/h5entrustweb?appid=***&contract_code=***&contract_display_account=123&mch_id=***&notify_url=***&plan_id=***&request_serial=16952&return_appid=wxcbda96de0b165486&clientip=127.0.0.1&timestamp=1567489267&version=1.0&sign=18870F7EDB52411B20EF733CED07C2FA7B854725C72948162AC6564B6C6BD1D3

然后获取到返回信息

<xml><return_code><![CDATA[SUCCESS]]></return_code>
<return_msg><![CDATA[]]></return_msg>
<result_code><![CDATA[FAIL]]></result_code>
<result_msg><![CDATA[INVALID_REQUEST]]></result_msg>
</xml>