Just enter the 1099-R as it is and it will go on the 1040 line 1.
You need to amend 2019 and enter the 2019 Traditional IRA contribution and make it non-deductible if that is what you want or your incime is too high to deduct. That will add a 2018 8606 with the contribution on lines 1,3 and 14.
The 2020 8606 line 6 will be blank if you did not have any 2020 distributions and line 14 will be the same as line 3.
**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.**
