As stated on the web page when you selected to pay the federal taxes owed with your credit card -
A convenience fee of 2.49% of total amount you owe will be charged by our credit card service provider. There is a minimum convenience fee of $3.95 regardless of your IRS payment obligation.
If you have not yet filed the 2023 tax return you can change your method of payment. If you have filed the 2023 tax return the method of payment cannot be changed.