What is the ruling on working in a pharmacy in America that defrauds insurance companies by dispensing medications to patients for cash, or dispensing medications paid for by insurance that the patient does not need, knowing that leaving the job is very difficult due to sponsorship and its effect on residency with the husband?

If your work in the pharmacy does not involve insurance, then there is no harm in it. However, if you are performing work that involves defrauding insurance, then if the insurance is commercial, which is usually the case, it is permissible for patients to defraud to benefit from the extent of the premiums they have paid, and it is permissible for you to assist them to this extent. But if the insurance is cooperative, it is not permissible to defraud to benefit from it or to assist in that in any way; due to the Almighty’s saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." In this case, you must leave the aforementioned work.