You specify the main URL because the online search engine could have problems analyzing which one particular really should be the principal URL.  The following tutorial will teach you ways to help Canonical URLs in Prestashop one.5. PrestaShop modules we developed 1st to resolve the situation of our own https://bookmarkingdelta.com/story19168146/about-automatic-hreflang-tags-canonical-tags-all-pages-seo