You specify the main URL since the search engine might have difficulty identifying which a person needs to be the principal URL.  The following tutorial will explain to you ways to allow Canonical URLs in Prestashop one.five. The JS redirect seems like a little a messy problem, but to https://addons.prestashop.com/en/seo-natural-search-engine-optimization/31857-automatic-google-rich-snippets-json-ld-open-graph-seo.html