Backdoor Roth IRA conversion with prior year nondeductible balance

I had a $6000 balance in my traditional IRA which was nondeductible in 2021.  In 2022, I made another $6000 nondeductible contribution to my IRA and then immediately converted all $12000 to Roth IRA.  I received a Form 1099R indicating $12000 distribution with box "taxable amount not determined" checked. I have tried to enter this into turbotax for my 2022 tax return but it keeps on characterizing the $6000 from 2021 as taxable distribution even though it was a nondeductible amount.  I verified from my 2021 tax return that it was properly characterized as nondeductible.  I am trying to follow instructions from older posts but looks like the questions have changed in the 2022 software, and I cannot figure it out how to do it in the forms view.

 

How do I solve this problem?

 

Thanks.