Deceased father's RMD 2021

My father passed away in April 2021 and he had not yet taken his RMD for 2021.  He was over 80 and was required to take a yearly RMD .   My sister and I are the beneficiaries of his IRA (now considered an "Inherited IRA" to us.)  Since he did not take his RMD for 2021 prior to his death, my sister and I as the IRA beneficiaries, are required to take it for 2021 and report it on our personal taxes, otherwise we incur a tax penalty of 50% of the RMD.   (We have taken the RMD.)  

My question is, I am completing my father's final personal Return for 2021 (the year of his death). How do I answer the RMD question since he didn't take it.  If I mark that he didn't, then Turbo Tax  goes into information requesting a Waiver from the IRS.   I feel like I'm missing something.  Turbo Tax is usually good at creating different tax scenarios for examples, but other than asking whether or not the filer is alive in the initial profile set up, it doesn't address any tax items that might be affected by his death.