def export_status
    export_result = ExportTaskResult.where(:token => params[:token]).first
    if export_result
      file_url = export_result.file.present? ? export_result.file.expiring_url(ExportTaskResult::AWS_S3_URL_EXPIRES_SECONDS) : nil
      render json: {token: export_result.token, status: export_result.status, url: file_url}