Hi Rajni,
Thank you for contacting the Syncfusion support.
Can you please confirm your requirement is about html exporting? If html export, we have prepared the sample with html export options.
In DocumentEditor, you can open and save html file using Syncfusion Docio library.
We have prepared sample with html export options and get it from below link:
Note: The file will save in wwwroot/Files folder.
Can you please confirm provided sample satisfied your requirement?
Regards,
Suriya M.