签名主体：

POST

/v3/transfer/batches

1719453920

ac2e8e67-5b1e-494d-894a-28a73b1207b2

{"appid":"wxe366000000006df2","batch_name":"20240627100448570-商户转账","batch_remark":"商户转账给用户","out_batch_no":"c818296472034729b3d7eef987b737fc","total_amount":1,"total_num":1,"transfer_detail_list":[{"openid":"oywtJ600000Nlen007JScJq2zQms","out_detail_no":"c818296472034729b3d7eef987b737fc","transfer_amount":1,"transfer_remark":"提现"}]}

Authorization

WECHATPAY2-SHA256-RSA2048 mchid="1600000002",nonce_str="ac2e8e67-5b1e-494d-894a-28a73b1207b2",timestamp="1719453920",serial_no="685D0000EA500000000000000438387800002CB5",signature="Kk4iNgi0mgPkpiDyxEyqYTzeLWZaFQS64nLBkWO6/x6eofeh6l2+o1sMR+suOSBU4eYe74ObFA/sc+HBkME4q54mz71DMUoY3kXONWitvF8ovr2F1vNlPMBap03FKTawab58dAYPvGLTqR7iijblOsHILGypL+QUvMgenp99/YsSaH391gCmf+qT/b649bMhfYfy/jxytmz0NzyqFmSxD5S9LxKm8Jkaet3FdFzhUO80Wx3BW8rP1YnRnqLtsd030Py6io0cuhLH262hzSOfJeQ99PqQyg4zR8fE2COvXG+gLNk2lcUSffw8QZX8f5YEwIFIM1CcPjgT/O08Ct6SrA=="

签名和参数验证没有问题 但是请求接口：https://api.mch.weixin.qq.com/v3/transfer/batches

远程服务器返回错误: (400) 错误的请求。

请问这是为啥呢？