You specify the primary URL since the search engine can have issues figuring out which a single need to be the principal URL.  The subsequent tutorial will demonstrate the way to allow Canonical URLs in Prestashop 1.5. By default, PrestaShop's deep URLs (that is, particular pages as an alternative https://addons.prestashop.com/es/seo-posicionamiento-buscadores/31857-google-rich-snippets-automatico-json-ld-opengraph-seo.html