If you didn't have any distributions form your plan in 2020, you can delete the Form 1099-R and add it again in 2021.
How to delete form in TurboTax online:
Open or continue your return in TurboTax. In the left menu, select Tax Tools and then Tools. In the pop-up window Tool Center, choose Delete a form. Select Delete next to the form/schedule/worksheet in the list and follow the instructions
