It is possible to force so as to add "http" or "https" prior to the canonical URL (to stop duplicate involving the http and https Edition of a web site). Ex: if you decide on to drive https with the canonical URL, the canonical URL of your site are going https://addons.prestashop.com/it/seo-indicizzazione-naturale/31857-google-rich-snippet-automatico-json-ld-open-graph-seo.html