" GTM no-script code not found: possibly missing or not in " I try out to incorporate the script within the header.tpl but there is no part. Update: Dilemma was solved. I just use Yet another addon and customise hook to do it. Many thanks Ali Edited November 21, 2018 https://addons.prestashop.com/fr/seo-referencement-naturel/30904-balises-hreflang-automatiques-et-balises-canoniques-seo.html