✅ Content would exceed Content-Length

    public void AddFile(string filePath, string fileName) {
      // Open the file stream
      FileStream fileStream = new(filePath, FileMode.Open, FileAccess.Read);
      _fileStreams.Add(fileStream);

      // Create stream content and add it to the form data.
      StreamContent streamContent = new(fileStream);
      streamContent.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
      _formData.Add(streamContent, "file", fileName);
    }