Before you can purchase Credits or REX for your account you must have at least one level 10 character that you've logged into recently on your account.
In order to purchase Credits in the Rift Store, first open the store menu by clicking the cart icon on the bottom left-hand corner of the screen.
Once in the RIFT store, click on the square shaped button with the green diamond icon.
In the new menu, there will be different types of Credit packages that can be purchased. Select the package you want to purchase, then select the payment method and click on the ‘BUY NOW’ button.
After the purchase is complete, it will take a few seconds to process and then the Credits to be added to your account. Once they are available, a popup will occur with the amount of Credits you purchased. You will then be able to make purchases using those Credits.
We also have a tradable credit consumable called REX (RIFT Exchange) that you can purchase in this store. If you want more information on that please visit our community post here.