请求微信接口返回的数据：

array:3 [
  "code" => "SIGN_ERROR"
  "detail" => array:4 [
    "detail" => array:1 [
      "issue" => "sign not match"
    ]
    "field" => "signature"
    "location" => "authorization"
    "sign_information" => array:4 [
      "method" => "POST"
      "sign_message_length" => 92
      "truncated_sign_message" => """
        POST\n
        /v3/marketing/favor/stocks/15052364/start\n
        1600756954\n
        MGUuy2siR40IgADtkelHh5V91LFqvKd6\n
        \n
        """
      "url" => "/v3/marketing/favor/stocks/15052364/start"
    ]
  ]
  "message" => "错误的签名，验签失败"
]

这是PHP的代码过程，一切都是按照文档的写的，GET方式的请求是正常的，POST请求就是一直提示签名失败，况且Authorization请求头信息不管是GET还是POST都是一样的，请求官方该如何排查这个问题，查了三天，也没有找到问题所在之处？