In 2023, Form 1099-R will have a distribution code box 8, Return of contribution taxable in 2023, UNLESS

it is taxable in the prior year(2022) for the excess401k contribution. "Return of contribution taxable in 2022" received in 2023 on Form 1099-R 2023, will show code P. Then you have to amend 2022.

It stinks that the 2023 Form 1099-R reports 2022 income.