"I have an estimated $ he received, not the actual payments."

If this is UI, they can print their UI transactions. They can ask the IRS for their tax transcript for 2020, to see what others have reported in their SSN. And get their banking, and account for the time shift; the deposit date for the first deposit in Jan likely is reporting as Dec benefit.

That makes 3 ways to get what you need. You didn't explain why they can't get a 1099-G, either. Who got it?