appId：wx7ce68c29d7bbf8b0

商户号：1259253401

urlhttps://api.mch.weixin.qq.com/secapi/pay/refund参数：<xml><appid>wx7ce68c29d7bbf8b0</appid><mch_id>1259253401</mch_id><nonce_str>1643411277314656256</nonce_str><notify_url>https://test.doctorpanda.com/panda-payment-web/payment_refund/appRefundCallback</notify_url><op_user_id>wx7ce68c29d7bbf8b0</op_user_id><out_refund_no>20220307170344857824</out_refund_no><out_trade_no>20220307102701860596</out_trade_no><refund_account>REFUND_SOURCE_UNSETTLED_FUNDS</refund_account><refund_fee>2</refund_fee><sign>7EBF6CD56ED9A1C7A03323920FF06798</sign><total_fee>2</total_fee></xml>请求结果：<xml><return_code><![CDATA[FAIL]]></return_code>

<return_msg><![CDATA[证书已作废]]></return_msg>