Save Document as html does not save page headers and footers

Can you please tell me how to include the document headers and footers when using the

Document.save(documentfilepath, saveFormat.html)

Hello!
Thank you for your inquiry.
Headers and footers are exported to HTML by default. But there are some restrictions on them. As you know headers and footers can be different for first and other pages of a section, for odd and even pages. That’s impossible to output all headers and footers to HTML meaningfully.
In the current implementation Aspose.Words outputs only primary header and primary footer for every section if any are present. This is questionable. If there are different header and/or footer for the first page in a section then you are getting a surprise.
It’s better to suggest something if you attach a sample document and explain what behavior you’d like to see from Aspose.Words. In most cases you can do a programmatic workaround by removing unneeded headers and footers and inserting primary headers and footers before conversion.
Also you can completely disable output of headers and footers by setting property HtmlExportHeadersFooters to false. See documentation on class SaveOptions for details:
https://reference.aspose.com/words/net/aspose.words.saving/saveoptions/
Regards,