you will get a 1099-R in 2023 showing the excess earnings.
meanwhile the custodian will return the earnings to you so you will know the answer.
If positive, you want to include that excess on your 2021 tax return, 1040 Line 4b.
Request a 4868 extension if necessary.
Otherwise you will have to amend your 2021 tax return next year.
If negative, the amount of earnings to report is zero.
