I called my credit card and they said it will be up to the vendor how will they charge the charges. I'm not sure how TT processes theirs but Payusatax.com will charge 1.85% convenience fee and the charge will be a regular purchase and not a cash advance. #12 of https://www.payusatax.com/IRS/Home/LoadStaticPage?pageName=FAQ#12
https://www.irs.gov/payments/pay-your-taxes-by-debit-or-credit-card
