As anticipated, you can have sex with prostitutes in exchange for a small fee in Cyberpunk 2077. There are only two sex workers in the whole Night City: a man and a woman. Your gender don't matter: they will offer the same service whether you chose to play an man or a woman.
The two sex workers are in the same place, in Westbrook, Japantown, a few meters from each other. They are marked by a kissing lips icon on the map.
You'll have to pay 100€$ to trigger a sex scene, and you can do it whenever and as often as you want.
Note that it won't affect your character in any way, and there are no trophies linked to that action.