What is the ruling on the financial compensation I receive for extra work training postgraduate students specialized in banking, given that these banks are usurious?

It is not permissible to teach students accounting systems if it is for the purpose of working in usurious banks, because it is considered cooperation in sin and aggression. Likewise, it is not permissible to take the money obtained from such teaching, because it is money acquired through unlawful means, and it must be disposed of by spending it on the welfare of Muslims.