01) Access control panel
02) After login click Modules >> Orders
03) Select the module of Additional Fee by type of payment
04) After clicking the Install button
05) After installing click the EDIT button
06) Fill in the fields as requested to configure the module of Additional fee by type of payment
07) To view the payment module code go to the control panel >> modules >> payment >> by passing the mouse over the payment you can view the code to be filled in the Payment Type field to offer the additional fee by type of payment