Code J has nothing to do with a distribution from a traditional IRA.
If in 2024 you received a distribution of an excess traditional IRA contribution made in 2023 and need to enter the Form 1099-R before actually receiving it next year, the correct code is P on a 2024 Form 1099-R with the IRA/SEP/SIMPLE box marked. (If you received this corrective distribution in 2023, you will already have received the code 8 2023 Form 1099-R that you must enter).
