If you're in Japan, you can choose to pay at a convenience store.
You'll need to provide a number when paying. You can find your numbers on the Order History screen.
[How to View Order History]
Go to the Store tab, then tap "ORDER HISTORY" on the upper right corner of the screen.
[Convenience Store Payment Methods]
Payment methods vary by store. You can see how to pay at each store by tapping the links below.