Markup is usually easily checked by using schema markup tests Device. It will take a while for rich snippets to appear in search results, so they will not be shown immediately. Even so, product and class rich snippets will appear only just after Google indexes the written content. Step one: https://addons.prestashop.com/de/seo-suchmaschinenranking-optimization/31857-automatische-google-rich-snippets-json-ld-opengraph-seo.html