You put nothing down because you do not file any 5329 at all. If you told TurboTax that you did not take all of the 2018 RMD and it produced a 5329 then delete the 1099-R that you entered, delete any 5329 form and re-enter the 1099-R and answer the RMD question that a RMD was NOT required, because it was not required for 2018 if it was your first RMD and you deferred all or part to 2019.
Nothing about a RMD goes on a tax return at all, only the 5329 if the RMD was not taken if required and in your case it was not required at all in 2018so there should be no 5329 at all.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
