"The provision of a social media service, internet search engine or online marketplace by a group includes the carrying on of any associated online advertising service. An associated online advertising service is an online service that facilitates online advertising and derives significant benefit from its association with the social media service, search engine or online marketplace."
Google Ads for instance invoices the tax to their customers. https://support.google.com/google-ads/answer/9750227?hl=en-G...