It appears that the information requested on that screen is no longer required. The law in Indiana changed for 2024, so that all military pay is deducted from state income tax.
When I enter an active duty military W-2 in TurboTax, the military deduction is automatically applied on the Indiana return. When I prepare the state return I see the screen Military Deduction that tells me that the active duty military pay included in my federal return qualifies for a full deduction. Like you, I did not have a box to enter total military pay, but all of my military (active duty pay) was deducted. This document states that both active duty military and reservists may deduct all of that pay from their Indiana tax returns.
Thank you for bringing this to our attention.