Pro rata rule for IRA distribution

Hello experts,

 

I understand the pro rata rule for IRA distributions and calculated my taxable and non-taxable portion of my IRA withdrawal.   In my 2021 Turbo tax desktop software where you enter your 1099-R I don't know how to enter the different categories of distribution (taxable and non-taxable).   I'm using 2021 Turbo Tax to estimate my 2022 taxes and approximating what my form 1099-R would look like.   This is my first IRA distribution, so I never have a 1099-R as a template. 

 

I entered the total distribution in box 1 and the "calculated" taxable amount in box 2a. and my federal tax owed did not change.   In fact, other than entering $0.00 in box 2a. my federal tax owed does not change.  O

 

Any help would be greatly appreciated.

Thanks in advance,

Dave