Currently, when a note is exported to PDF, QOwnNotes does not add bookmarks to headings. Bookmarks are essential for document navigation and document structure.

Here are screenshots of PDFs with and without bookmarks.

PDF exported by QOwnNotes. Note how the 'Document outline' option near the top left is greyed out:

PDF created using LibreOffice, after copy-pasting QOwnNotes's preview panel contents:

Resources

While I'm no programmer, I believe the following links may be of use:

• List of All Members for QPdfWriter
• QPdfBookmarkModel Class
• Troubleshooting QPdfBookmarkModel: A Guide to Common Issues