颤抖的自定义方法“ REPORT” http请求

Question

我正在努力实现我可以在邮递员中完成的REPORT方法：

REPORT /remote.php/dav/files/UserName/ HTTP/1.1
Host: example.example.com.br
Authorization: Basic d3ByZW******ZWFubmV0
User-Agent: PostmanRuntime/7.17.1
Accept: */*
Cache-Control: no-cache
Postman-Token: 9c6c16ec-355a-408a-a5df-2095499ebfb9,1af9a0e6-641b-446a-9aa1-691ed79faa11
Host: example.example.com.br
Accept-Encoding: gzip, deflate
Content-Length: 0
Connection: keep-alive
cache-control: no-cache

<?xml version="1.0"?>
<oc:filter-files  xmlns:d="DAV:" xmlns:oc="http://example.org/ns" xmlns:nc="http://example2.org/ns">
    <oc:filter-rules>
        <oc:favorite>1</oc:favorite>
    </oc:filter-rules>
</oc:filter-files>

但是我不知道如何添加XML部分作为参数。我最接近的是Dio：

  Dio dio = new Dio();
  dio.options.method = 'REPORT';
  dio.options.headers = {HttpHeaders.authorizationHeader: basicAuth};
  Response response = await dio.request("$protocol://$baseUrl/$basePath/$us/");

在“ try / catch”块中进行测试时，返回以下内容： I / flutter（6407）：DioError [DioErrorType.RESPONSE]：Http状态错误[500]

感谢您的帮助，谢谢。