If you have not received your payment by January 15, 2021 you will claim the Recovery Rebate Credit by answering the two questions about the stimulus payments that will appear at the end of the TurboTax interview.
The questions are in the section Federal Review.
Once the information is entered you will see your refund increase or balance due decrease, and TurboTax will enter the amount of the credit on Line 30 of Form 1040 for you.
Please be advised that the IRS has sent a second round of payments out today, January 8, 2021. If you filed a 2019 tax return and received a refund via direct deposit, we encourage you to check with that bank today to see if you were included in this round.
In my case I got a partial for the 1st payment and it says I'm eligible for the 2nd but I didn't receive it. I did answer those questions but it isn't populating anything in line 30 on my 1040. How can I determine what should be there or fix it so it does populate?
If you did not receive your second stimulus check, then you will enter $0 or not enter anything in the box. Here is an IRS link to the IRS that explains how the Recovery Rebate Credit is calculated.