This is the print-friendly version of the article. It declares the main article page as its canonical because the content is identical — only the layout differs.
The canonical tag in the <head> of this page reads:
<link rel="canonical" href="https://robots-txt-lab.pages.dev/article">
Including /print-version in the sitemap tells Google it is an independent,
authoritative page — but its own canonical tag says otherwise. Google follows the canonical
and ignores the sitemap signal.