You are considered a successor beneficiary to someone who died in 2020 or later. This means that the 10-year rule created by the SECURE Act applies to you. No distributions are required to be made from this IRA until 2030 when any amounts that remain must be distributed to you (or to your beneficiaries if you should die before the account is fully drained) by the end of 2030.
In TurboTax, you'll indicate that any distribution you take is all RMD (since this question is really asking how much is not eligible for rollover and none of a distribution from this IRA is eligible for rollover) and that you have completed all of your RMDs with respect to this account even if you took none from this account (in 2030 you'll need to make sure that you've satisfied the RMD by distributing anything that remains).
