Is the failure to inform the government about income earned from teaching the Quran, which is set aside as a reserve until monthly assistance ceases, considered unlawful money, given the difficult living conditions and the inability to return to one's homeland?

If a Muslim enters non-Muslim lands under a covenant and a pledge of safety, he is obliged to abide by its laws and avoid taking what is not permitted by law, unless there is a necessity that makes the forbidden permissible. So, if the aforementioned salary is only given to those who have no income, then it is imperative not to take it.