@SJH57
If you took out the contribution and interest,
that means you did the calculation of interest yourself.
The interest has to be reported on Line 4b of your tax return for the year for which the excess contribution was made i.e. 2020.
You will explain what you did on 1040-X Part III - Explanation.
Do not include your old 1040 nor your revised 1040 because the Form 1040-X reflects any changes there and becomes your new tax return.
Your new AGI will be on Form 1040-X Line 1.
Note: if you just enter it as interest income, the effect will be the same.
