You specify the primary URL since the online search engine could possibly have problems pinpointing which one particular should be the main URL.  The following tutorial will teach you how you can permit Canonical URLs in Prestashop 1.5. Meta key phrases. Search phrases you will have to define as https://addons.prestashop.com/es/seo-posicionamiento-buscadores/31857-google-rich-snippets-automatico-json-ld-opengraph-seo.html