调用接口：https://api.mch.weixin.qq.com/v3/refund/domestic/refunds

申请退款请求参数：

{
    "out_refund_no":"2103092114001000",
    "out_trade_no":"2011131000001006",
    "amount":{
        "refund":1,
        "total":1,
        "currency":"CNY"
    }
}

申请退款响应结果：404 {"code":"RESOURCE_NOT_EXISTS","message":"订单不存在"}