Execution of a judgement to get maintenance for wife and child

My Muslim ex-husband is not paying monthly support for his Muslim son who is under my custody (I'm a Muslim too) from 2012 until now.

Dubai Court has ruled for AED 1K monthly support for him to pay, yet he has not paid anything. My child has stopped schooling because I cannot anymore support his school needs.

Now, I have no idea if he is still here in the UAE as the numbers we knew are not anymore working. Please advise generally, what should I do?

I went to Dubai Court recently but there is no penny paid. The amount is already nearly AED 90,000.

Thank you