To actually rank high in the country of your extension you should actually have a domain for each extension, and this is out of the box available in Prestashop.
1: create a multistore per url (domain.com, domain.fr, domain.de etc..)
2: only activate the language that is needed for that specific domain.
Or simply use this module: https://addons.prestashop.com/en/international-localization/49386-language-per-domain.html