I have no 1099R form because I took no distribution but cannot proceed without entering something?

It is likely that you accidentally entered a blank 1099-R form without meaning to (it's easier than you think).

Do a Search (upper right) for 1099-r and click on the jump-to link (Mac users must find 1099-R in the Topics List). NOTE: just type in 1099-r and hit Enter; do not try any of the suggested Search items.

This should bring you to a table of all the 1099-Rs you have entered. If you see one that has something like "untitled" for the title, then this is the blank one. Use the Delete button or the trash can icon to delete it, and resume the Review.

P.S., also, if you had a 1099-R in 2019, then TurboTax carried over the text part of the 1099-R for your convenience. If so, if you did not take a distribution in 2020 from the same plan, you will need to find and delete that 1099-R entry.