You specify the first URL since the online search engine can have problems identifying which one particular really should be the principal URL.  The following tutorial will show you ways to empower Canonical URLs in Prestashop one.5. Improve the indexing of your respective Prestashop urls in Google. This module https://getsocialnetwork.com/story4698862/the-definitive-guide-to-prestashop-hreflang-canonical-tags