Ref. No. 41/1022
In the name of Allah the most gracious the most merciful
The answer to your question is as follows:
It is not allowed to help others in sin. The Holy Quran says: “Help you one another in virtue, righteousness and piety; but do not help one another in sin and transgression. And fear Allah. Verily, Allah is Severe in punishment”. (Surah Maidah). So his salary thfough this job is Haram. He must quit the current job and look for an alternative Halal job.
And Allah knows best
Darul Uloom Waqf Deoband