var doc = new XDocument();//заполняем документ
    WebRequest request = WebRequest.Create(ftpAddress);

    request.Credentials = new NetworkCredential("login", "password");
    request.Method = WebRequestMethods.Ftp.UploadFile;

     using (Stream ftpStream =  request.GetRequestStream())
     {
        doc.Save(ftpStream);
     }

            try
            {        
                using (Stream ftpStream = request.GetRequestStream())
                {
                    doc.Save(ftpStream);
                }
            }
            catch (Exception ex)
            {
                _logger.LogError($"message:{ex.ToString()}");
                _logger.LogError($"innerException:{ex.InnerException.ToString()}");
            }

byte[] bytes = System.Text.Encoding.ASCII.GetBytes(doc.ToString());
request.ContentLength = bytes.Length;

   try
            {
                using (Stream ftpStream = request.GetRequestStream())
                {
                    doc.Save(ftpStream);
                }
            }
            catch (Exception ex)
            {
                var innerEx = ex.InnerException is null;
                _logger.LogError($"InnerExceptionNotExist:{innerEx.ToString()}");
            }