Fake “official” websites: how to tell, and what to do if you paid one
Type "ESTA" or "UK ETA" into a search engine and several of the first results are agencies. They copy the look of a government site, use the acronym in their domain name, and charge the official fee plus their own. Every government concerned warns about them on its own pages: GOV.UK ("Avoid websites that imitate government services"), CBP, Canada and the EU's ETIAS site ("There are many unofficial ETIAS websites").