can you provide any more detail?
did you file a 2020 or 2021 tax return? look at line 30 on each tax return. Any money due you should have been reflected there.
Otherwise, the filing for 2020 and 2021 is the way to get this money.
Alternatively, did you look at your transcript at the IRS website? if you see the stimulus payment listed in the 2020 or 2021 details and you didn't receive it (i.e. it was mailed and you enver received the check), they you will have to complete form 3811 and mail it to US Treasury. The IRS won't be able to help you out.
https://www.irs.gov/pub/irs-pdf/f3911.pdf
https://www.irs.gov/individuals/get-transcript
