The repayment will be reflected in your Form SSA-1099 for the year in which you repaid it. If you made the repayment in 2020 it will go on your 2020 tax return. If you did not make any repayment in 2019, you don't do anything about the repayment on your 2019 tax return. You just report the income as shown on your 2019 SSA-1099, as if it were correct. The repayment will be dealt with on your 2020 tax return.
The amount you repaid is, or will be, shown in box 4 of your SSA-1099. The net benefits in box 5 is the gross benefits in box 3 minus the repayment in box 4. Basically you just enter the amount from box 5 in TurboTax. There are special provisions if you end up with a negative amount in box 5. We can help you with that if it happens.
You might want to read "Repayment of benefits" on page 5 of IRS Publication 915. Keep in mind that the current edition of Publication 915 is for 2019 tax returns.
