You specify the first URL since the online search engine may have trouble figuring out which one really should be the main URL.  The next tutorial will demonstrate how you can permit Canonical URLs in Prestashop 1.5. Rel=canonical should only surface while in the of the doc. A canonical https://www.presta-addons-modules.com/en/opencart-seo-automatic-google-rich-snippets-json-ld-integration-opengraph-twitter-tags-schemaorg.html