We do need include annotations in PDF export.
How can we achieve that?
How exactly do you see the annotations included in the PDF export. The default PDF export template tries to reproduce what you see in view mode, and by default in view mode you don’t see the annotations. Even when you activate the annotations, you only see an icon indicating the position where the annotation was inserted, which wouldn’t help in PDF export. If you click on the annotation icon to view the annotation, it opens a popover that floats over the surrounding content, hiding it. I doubt you want to hide that content in PDF export.
Do you want to see the annotations at the end of the print page that includes them? You’ll have to create a custom PDF export template in that case, and you’ll also need to number the annotations in order to understand which part of the content is linked to the annotation. This looks similar to the footnote macros https://extensions.xwiki.org/xwiki/bin/view/Extension/Footnote%20Macro use case.
Hope this helps,
Marius