In RakefetOnline, the Admin users can modify the option and control of how the convenience will work with online credit card processing.
The convenience fee has a few possibilities. It can be setup as optional with a % or price, or not included as an option with the % or price, or mandatory with a % or price.
If you give the member the option to pay the convenience fee, they can manage their choice with the convenience fee switch on their payment page:
The controls for the payment processing and the convenience fee controls can be found under Setup--> Payments
