Before managing the Ratepay payment methods, please ensure that you've setup the plugin before and that the credentials are being saved.
Once the Ratepay payment plugin is installed and the payment methods are activated, you can assign the payment methods to the shipping methods in Settings > Shipping costs.
- Switch to the tab payment method selection.
- Assign the Ratepay payment methods from Available to Selected.
Per default express shipping is not allowed when using Ratepay's payment methods. Talk to your Ratepay representative if you need those shipping methods in collaboration with Ratepay.
Please ensure, that you have excluded Ratepay from according shipping methods.