If I understand correctly, you took your 2023 RMD in 2024. If that's true, it has to be reported on your 2024 tax return, even though it's for 2023. You report any distribution from an IRA in the year that the distribution is actually made. You should also have taken your 2024 RMD in 2024. You should have gotten a 1099-R from Fidelity for the total that you took out in 2024: the 2023 RMD plus the 2024 RMD. You need a standard 1099-R, not a substitute 1099-R. If you didn't get the 1099-R in the mail, you should be able to download it from your account on the Fidelity web site. (If I understand correctly, "the receiving entity" is Fidelity, or your IRA at Fidelity.) Call Fidelity if you need help downloading the 1099-R, or you can ask them to mail you a copy.
