You specify the main URL since the search engine can have trouble analyzing which a single really should be the main URL.  The following tutorial will tell you about ways to allow Canonical URLs in Prestashop 1.five. Canonical URLs are applied to stay away from copy content and to https://addons.prestashop.com/pt/seo-referenciamento-natural/31857-rich-snippets-automaticos-json-ld-opengraph-seo.html