Credit card payment for taxes due is an option that you will see offered in TurboTax, but it may not be a wise one.
Be aware there is a huge service fee if you pay that large an amount by credit card. I don't know the exact percentage, but it's like 2% or so. That would be a $140 service fee on that amount.
You could choose to have it electronically debited from your bank account for free. That's one of the options in the TurboTax program, or you can go to the IRS site below after filing and pay the tax due there directly out of your bank account using Direct Pay, which is also free:
https://www.irs.gov/paymentsIf you pay there, you can print a confirmation page for your records. With the confirmation number you can check on the status of your payment, etc.
Your bank statement is also proof.
Another option is to mail a payment voucher and paper check. If you did that, I'd use a method that has tracking, such as certified mail, priority mail, etc.
