If you know what a pit is in brick-and-mortar casinos, then the term pit manager is sort of self-explanatory.
Namely, as we’ve mentioned above, casinos have either one or several pits, and a pit manager, also known as pit boss, is the person who manages table games in a pit. It is their job and responsibility to ensure that everything works smoothly. They keep an eye on the players as well as the croupiers. Furthermore, they are there to resolve any issues or disputes that occur during their shift, such as dealing with angry or dissatisfied players.
Needless to say, they have a great deal of authority within a casino, so you should treat them with the utmost respect, which can be said for any other casino employee, for that matter.