Is it permissible to work as a cashier in a gambling hall, given the aversion to this work and the lack of any other job, knowing that he is married?

If the nature of the work facilitates gambling or any other forbidden act, then it is impermissible to continue in it, as it violates the verse: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." One must repent and leave such work, and perhaps Allah will replace it with something better. "And whoever fears Allah - He will make for him a way out and will provide for him from where he does not expect." It is advisable to seek help from righteous people to find another job. However, if the work is not related to gambling or any forbidden act, then there is no harm in it, though it is better to seek another place to avoid witnessing forbidden acts.