The IRS has not yet issued the form for reporting the income on the 2021 tax return. TurboTax will include the form as soon as possible after the IRS issues it. There is no date for when it will be available. It will be Form 8915-F.
When the form is available you will enter the income in the retirement section. If you did not receive any 1099-R for 2021 you will say that you did not receive a 1099-R. Then it will ask about a 2020 distribution that you chose to spread over three years.