Since the distribution occurred in 2019 the rollover is reported on your 2019 tax return. You do this by entering the 2019 Form 1099-R (required to be made available to you by the payer by the end of January) into TurboTax and in the follow-up indicating that you moved the money to another retirement account (or returned it to the same account) and indicate the amount rolled over. It's reported this way even though the rollover within 60 days occurred after the end of 2019.
