The article explains how UK online slots are tested and regulated differently...

https://www.bookmark-belt.win/uk-and-us-slot-rules-differ-in-ways-players-may-not-notice-ukgc-testing-sets

The article explains how UK online slots are tested and regulated differently from those in the US, where rules vary by state. It notes that UKGC testing checks games before release, while some states allow sports betting but not online casino play