To make a single payment 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 use the Make a Payment widget on the payment screen. You will select the account from which you are paying, the amount, and the date of the payment. Click “Make Payment” to set the instructions.