Which payment method should I be using to pay online?

I'm here because nobody f*c*ing picks up every IRS number I've called, and not even sure if my local tax office is even open anymore. I owe taxes to the IRS for 2025. I've set up my online profile, and based on past threads suggesting I pay what I can despite my outstanding balance not being reflected anywhere, I submitted a payment under "2025 Income Tax" for a sizeable amount. The payment went through and I see that reflected in my bank account.

Today, I finally got my letter noting how much I owe based on my Form 1040. When I checked the payment options, I see a separate 1040 payment option under "Pay towards my balance" with the option of a specific tax year. Was I supposed to pay my taxes owed under this method? If I paid under the "2025 Income Tax" and not the "Pay towards your balance", is the IRS smart enough to know that I was trying to pay my outstanding balance will my earlier payment go towards my amount due?

And better question: how can I get ahold of anyone at the IRS to answer this question? Can/should I just show up to my local office without an appointment to verify payment?