Deductions & credits
You must indicate you have a credit from Form 8801 from your 2020 tax return. You can review your 2019 and 2020 tax returns to be sure the credit does continue to carryover. If so you can select the checkbox 'My 2020 return includes Form 8801' then enter your amount. You do not have to amend before you file your 2021 tax return, but you should amend the 2019 and 2020 to show the carryover is present.
