There is certainly not any cost-free addon for installing Google Tag Manager in PrestaShop other than buying a paid out addon. Prestashop also doesn’t give usage of Web page code so we will increase Tag Manager code but there is still an alternate way by immediately modifying the website code https://www.presta-addons-modules.com/en/seo/prestashop-seo-automatic-hreflang-tags-canonical-tags-on-all-pages.html