Currently, we do not have exporting support, and we have planned for PDF and Excel exporting support in Gantt for Volume 3, 2019 main release.
You can track the status of these feature by using below feedback links.
Can you please elaborate your requirement to use Gantt as OOB file such as what will you do with exported OOB file in your application?
Please update the details to focus on the specific area to help you better..
Jesus Arockia Sankaran S