var resourcesFolder = 'C:\\Files\\sample.docx';
fs.readFile(resourcesFolder, (err, fileStream) => {
  // construct FileApi
  var fileApi = groupdocs_signature_cloud.FileApi.fromConfig(config);
  // create upload file request
  var request = new groupdocs_signature_cloud.UploadFileRequest("sample.docx", fileStream, myStorage);
  fileApi.uploadFile(request)
});