Help please! SOLD small Trad IRA, Box 2 Taxable Basis Incorrect. How can I correct/change in 2024 TT Deluxe?

@DaveF1006  or @dmertz   Anyone...please help. I'm at a loss trying to figure this out. We sold a Traditional IRA and closed the account in 2024. No contributions made. 1099-R Box 2a has the "Taxable Amount" wrong (so I don't want to pay extra tax on money that was ours--part of the actual Basis.)  
I'm at a loss trying to figure out how to get that basis number corrected. I know I can't change the 1099-R, but cannot find any worksheets or forms available to me. In searching TurboTax, Form 8606 came up, but I don't have access to it and it looks like more for a backdoor roth on contributions.  

 

I really need guidance please.  I don't usually wait until the last minute, but mother died recently and still need to do her taxes also after I figure this out. Can't afford to extend with a wedding in a few weeks and mom's estate to deal with either.  Online you both sound like you know what you're doing! Guidance please.