Only the 3rd stimulus payment will be asked on the 2021 tax return.
For the other 2 stimulus payments issued in 2020 you will need to amend the 2020 tax return for the Recovery Rebate Credit if you did not receive those payments.
See this TurboTax support FAQ for amending a 2020 tax return - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-return/00/27439
