https://www.irs.gov/newsroom/recovery-rebate-credit

The first step for something like that is to always look at the current year form to see if there is someplace on the form that the information would be entered.

Not for a 2022 return.  

They still could have filed a 2021 return, even if no tax liability would arise.  File an accurate 2021 return, they will get the rebate, and you will be a hero!

Or they got it and forgot about it, so you are going to look like a goat when the IRS bounces the return😉

I don't think the IRS would even bounce it back... but your clients would call you every 2 weeks wondering where's the refund.........

IRS would "correct" it by not issuing a refund.

If they filed a 2019 or 2020 return and/or receive gov't money, they most likely received the EIP already.