While Gary Illyes, a Google analyst, believes that search engines like google might depend fewer on hreflang plus much more on automatic language detection in the future, for now, the tag is our greatest guess.  Adding this code to every site of your website might be inconvenient and impractical, but https://bookmarkvids.com/story20060486/not-known-factual-statements-about-prestashop-google-tag-manager