Form 8606 = where to input the basis of a second IRA. Pro-rata rule

In 2024, I contributed $8000 non-deductible money to an IRA.  And then did a backdoor conversion to a Roth IRA.  I neglected to convert a second IRA held with another company to a Roth IRA.  I'm in the process of filing an amended 2024 return because I didn't file Form 8606.  Where in turbotax do I report the 12/31/2024 value of the second IRA I own because of the pro-rata rule.  Thanks for any and all help!