If you did not receive your first and/or second stimulus payment or if the amount received is not correct, you can claim it on your 2020 tax return as the Recovery Rebate Credit.
In TurboTax Online, to claim the Recovery Rebate credit please do the following:
It seems you are looking for a Form to use in for the Recovery Rebate.
If eligible, you can claim the Recovery Rebate Credit when you file your 2020 tax return (Form 1040 or Form 1040-SR) electronically using tax software or on paper. The 2020 tax return instructions include a worksheet you can use to figure the amount of any Recovery Rebate Credit for which you are eligible. The worksheet requires you to know the amounts of your Economic Impact Payments. This is a link to the paper worksheet. https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
However, you may file using TurboTax Online:
In TurboTax Online, to claim the Recovery Rebate credit please do the following:
Your Recovery Rebate Credit amount will be phased out if your adjusted gross income for 2020 exceeds $150,000 if you are married filing a joint return or filing as a qualifying widow or widower, $112,500 if you are using the head of household filing status, or $75,000 if you are using any other filing status.