What is the ruling on working in hotel reservations for clients intending to travel to non-Islamic countries to commit immoral acts, and is the money earned from this work unlawful, and is it permissible to continue in this work to pay off debts?

Working in the tourism sector is often not free of objectionable things, and what you mentioned about some of the company's clients intentionally seeking out immoralities and abominations confirms this. We advise you to leave this job and look for another, for whoever abandons something for the sake of Allah, Allah will compensate him with something better, and "And whoever fears Allah - He will make for him a way out And will provide for him from where he does not expect. And whoever relies upon Allah - then He is sufficient for him." Your debt does not justify your staying with the company, because it is the duty of religious people to grant you respite if you are in hardship, "And if there is any debtor in difficulty, then grant him time until it is easy for him to repay."