A UKGC licence is the starting point, not the whole story. Check that RTP...

https://wiki-dale.win/index.php/Where_Can_I_Find_Game-Level_RTP_on_UK_Slot_Sites%3F

A UKGC licence is the starting point, not the whole story. Check that RTP figures are easy to find, withdrawals have clear timeframes, and responsible gambling tools are easy to access