def get_object(self):
        """Get the page by the id in the url here instead."""

        # This might happen when there is a preview request for
        # a page that doesn't exist, and now FeinCMS wants to
        # show a 404 page via FEINCMS_CMS_404_PAGE.
        if len(self.args) < 2:
            return super().get_object()

        page = get_object_or_404(self.page_model, pk=self.args[1])
        # Remove _preview/42/ from URL, the rest of the handler code should not
        # know that anything about previewing. Handler.prepare will still raise
        # a 404 if the extra_path isn't consumed by any content type
        self.request.path = page.get_absolute_url()

        return page
Get the page by the id in the url here instead.
feincms/contrib/preview/views.py