Is this your first RMD? Did you just turn 70 1/2 in 2019? If so, you have until April 1, 2020 (not April 15) to take your RMD for 2019. In that case the distribution is not late yet. If you take the distribution by April 1 there will be no penalty.
If you turned 70 1/2 in 2018 or earlier, the distribution is actually late. In that case, take the RMD for 2019 as soon as you can in 2020. You have to file Form 5329 with your 2019 tax return. Form 5329 calculates the 50% penalty for not taking the RMD on time, but you can request a waiver of the penalty. You will almost certainly get the waiver if taking the RMD late "was due to reasonable error and you are taking reasonable steps to remedy the shortfall." Taking the RMD in January is a reasonable step to remedy the error. To request a waiver you include Form 5329 and an explanation statement with your tax return.
If you have any Form 1099-R for 2019, after you enter all your 1099-Rs and proceed through the interview, you will come to a screen that asks you if you received all the RMD that you were required to take for 2019. If you answer that you did not, it will lead you through requesting the waiver and entering an explanation. In the explanation, in addition to a brief of explanation of why it was late, be sure to say that you took the distribution in January.
Unfortunately, there is a defect in the TurboTax interview that makes it impossible to fill out Form 5329 in TurboTax Online if you did not receive any 1099-R for 2019. The only way to do it is in forms mode, which is not available in TurboTax Online. That means you will have to use the CD/Download TurboTax software instead of TurboTax Online to file your 2019 tax return.
You still have to take your 2020 RMD before the end of 2020, so you will have the RMDs for two years on your 2020 tax return.
In the future, request your RMD earlier in December to make sure it gets done before the end of the year. It often takes a few days for the distribution to actually be made.
