" GTM no-script code not found: either missing or not in " I consider to add the script while in the header.tpl but there's no section. Update: Difficulty was solved. I just use A different addon and customize hook to get it done. Many thanks Ali Edited November 21, 2018 https://addons.prestashop.com/en/seo-natural-search-engine-optimization/30904-automatic-hreflang-tags-canonical-tags-all-pages-seo.html