Stimulus checks going to the custodial parent for back child support.

Hi,
I know someone asked this question, but I was wondering if you have found anything out yet? My ex owes about $42,000 in back child support, doesn’t have a payment plan set up, and he knows he didn’t get one because of back child support. But now the question is, if it was to go to back child support, when is that suppose to happen? I am not sure anyone can answer how they are doing that process, but is there any information about when custodial parents are suppose to receive those stimulus checks for back child support of it qualifies to go to them? I have researched google as much as possible and it’s all the same information. I guess one day it magically might be there or not? I wish there was more information so I knew if my kid would be getting it, or not. Like I said I know for a fact he didn’t get one, but the other parents like me are wondering if we’re getting theirs, or not, or even when that process might happen. I figured I would ask you, and give it a shot. Thanks so much.