There are definitely people who are enslaved in the UAE under the Kafala System. It’s unclear to me how widespread it is, but it does happen. When I was there, I personally met a woman on Tinder, and on our date she told me she had been forced into prostitution by the person who brought her to the UAE. She had to earn tens of thousands of dollars to get her passport back from him.
https://en.m.wikipedia.org/wiki/Kafala_system