The administration can choose to permit or disable currency and language auto-modify capabilities. Also, alter the default store currency and language from the module management page. In my code case in point, only when printing a document must all text be established in black versus a white (the paper) background. https://www.presta-addons-modules.com/en/seo/prestashop-seo-automatic-hreflang-tags-canonical-tags-on-all-pages.html