You specify the primary URL since the search engine can have issues figuring out which a person needs to be the principal URL.  The subsequent tutorial will provide you with ways to empower Canonical URLs in Prestashop 1.five. Enhance the indexing of the Prestashop urls in Google. This module https://addons.prestashop.com/it/seo-indicizzazione-naturale/31857-google-rich-snippet-automatico-json-ld-open-graph-seo.html