AMP Page URL is Forbidden (403)
This means that the URL in question defines an AMP Page URL that is Forbidden (403).
Why is this important?
If an AMP Page URL is forbidden, search engines may be unable to crawl the page and access the content, which means it may not get indexed or appear in search results.
What does the Hint check?
This Hint will trigger for any internal URL which references an AMP Page, where the AMP page URL returns a 403 HTTP header response.
Examples that trigger this Hint
Consider the URL: https://example.com/page-a/
The Hint would trigger for this URL if it included a <link> tag that referenced an AMP page:
where this AMP page had a 403 (Forbidden) header response:
How do you resolve this issue?
AMP URLs need to be accessible in order to be indexed. In this case, the server refused to serve Sitebulb the page when it requested it. This may indicate an issue in the server setup, or it might simply be the case that the <link> tag is pointing to the wrong URL.
To rectify, you would need to ensure that the <link> tag is pointing to the correct (i.e. equivalent) AMP page, and ensure that this page is fully accessible to search engines and users alike, returning a 200 HTTP response.
One other thing to note is that the 403 (Forbidden) response MIGHT NOT be the same response given to a search engine crawler. Sometimes, servers employ over-zealous firewalls or 'DDoS protection services', that detect crawling activity and treat it as a DDoS attack, which can lead to 403 responses. So it is worth checking the source of the 403 before taking action.