Well the Second Stimulus payment for 2020 could have come in Jan or Feb 2021. That was still reported on your 2020 return. The 3rd Stimulus payment came out starting in March 2021 and is for 1,400 per person. That is the only one you reconcile on your 2021 return. The IRS should have sent you letter 6475 to tell you how much they sent you. If you are married you should each get letter 6475 for half.
