Child support and allowance

Anonymous question.

Small backstory before I go into the question…
My 15 year old does not belong to either me or my husband biologically but we are his legal guardians. It has been that way since he was 18 months old.
Anyways, his biological father pays $80 a month for child support. I am very strict as to what that money is used for. It pays for his playstation subscription, buys his hygiene products, gas if we wants me to take him places to hang out with his friends, ect. It’s not very much at All.
All of my kids were getting $15 a week for an allowance. We have three kids. Y’all do the math.
My husband and I are both out of work right now so we don’t have the extra money to pay them their allowance but we have told them as soon as we start working again, they will get their allowance back. My 15 year old has now thrown a giant fit because we have not agreed to pay him his allowance out of the little child support money we get. He says that him doing his chores free of pay is illegal and child slavery. I would really like some advice or opinions. What should I do? What would y’all do?