W3c is your body that tries to standardize these things, they write The foundations, then programmers create their rendering engine to interpret People rules. The module is often mounted and configured from the PrestaShop again-Business, and it could be added for a block on the website's footer or header. When https://www.presta-addons-modules.com/en/prestashop-live-chat-support-with-zopim-zendesk-chat.html