RMDs are waived for 2020, which means they are effectively canceled. I did not take my RMD for 2020. I do not have a form 1099-R for that reason.

Nothing. You have no reason to enter the form if there is no physical form. 

You may have to delete the form.

Here's the general procedure for viewing the forms list and deleting unwanted forms, schedules, and worksheets in TurboTax Online:

1. Open or continue your return in TurboTax.
2. In the left menu, select Tax Tools and then Tools.
3. In the pop-up window Tool Center, choose Delete a form.
4. Select Delete next to the form/schedule/worksheet in the list and follow the instructions.