Pleasant URLs are being established during the configuration web page of each product, category, or static material site. This development web site is barely handy for many automatic web pages, and most of the time you will not have to worry about these.   You specify the main URL because https://www.presta-addons-modules.com/en/seo/prestashop-seo-automatic-hreflang-tags-canonical-tags-on-all-pages.html