I owe $2 in tax to the state of AZ. I am a resident of CA. TurboTax is prompting me to fill out AZ Form 309. Where do I find the amount subject to tax in both states?

Generally, you would claim the credit on your resident state for taxes paid to your nonresident state. However, CA and AZ are an exception to the rule. 

So in this situation, you would file your CA return first and then TurboTax will transfer your resident state return numbers to your AZ nonresident return.  

Unless, there is a number that is different for a reason, then you will not enter anything on the screens where it says Amount if Different.

When you get to the California Income Information screen, you will enter the full amount that was reported to CA which should be ALL of your income since you are a CA resident as the portion taxes by CA.  This will enter the numbers on Form 309 to give you the credit for taxes paid on the same income to CA. 

(Edited 4/2/24 @ 10:03AM PST) @bishopfamily