Marfeel-produced AMP pages respect a publisher's canonical URL. That means that Marfeel displays the canonical URL in the publisher's AMP URL for the article's AMP version.
This is important because a specific article can be accessed through different URLs due to multiple URL structures for article syndication through different channels.
Respecting the canonical URL for AMP pages ensures that Google can properly identify and extract the correct article, and then index and rank it appropriately. This is also relevant so that Google can associate an AMP page with the article's web version.
If a publisher has the following canonical URL defined in their source code for an AMP-activated article:
<link rel="canonical" href="https://www.example.com/uk/movies/reviews/justice-league">
The AMP URL for the same Marfeel-produced AMP article that respects the canonical will be: