To set up AutoPay on your Grand Reserve World Mastercard, first you'll need to sign into your account at https://secure.grandreservecard.com
After successful sign in, click on the Card - Payments section.
Next, ensure you have at least one payment source added (see How do I add a payment method?).
Next, select the options from the AutoPay widget. Select which payment account to use, when you want the AutoPay to occur, and what amount you want to pay (e.g. minimum due, full balance, etc.).