A non Gamstop casino is an online gambling site that operates outside the UK's Gamstop self-exclusion program

https://live-dealer-insider.trexgame.net/casino-non-gamstop-understanding-side-bets-and-house-edge

A non Gamstop casino is an online gaming website that runs outside the UK's Gamstop self-exclusion program, allowing gamers to delight in gaming without constraints.