When prompted to "Enter your qualified energy property costs," is cost the full cost (which was financed) or the amt actually paid 2024? $12,899 (full) v $3230 (actual)?

I bought a qualifying heat pump in 2024; the total cost was $12,899, but it was financed. This year, I made payments of $3230 toward that amount. What is the "cost" I should enter as a qualified energy property cost for the energy efficency tax credit, the $12899 or the $3230?