The module automatically adds a default canonical url to all your product, category, CMS pages only. By default, the module utilizes The existing url with the site since the default canonical url. You should utilize Ahrefs to unravel this problem – just go to the list of pages that link https://www.presta-addons-modules.com/en/opencart-seo-automatic-google-rich-snippets-json-ld-integration-opengraph-twitter-tags-schemaorg.html