If you do not want to purchase products on Boom Learning via Paypal, you can also enter your credit card information directly. Your payment information is stored on your account using an outside PayPal platform, called BrainTree.
To add a card, go to the Menu in the top right, then click My Settings. Then click the Membership tab to see your payment information. The screen you are looking for looks something like this:
Simply click Add Card and enter your information to store it with BrainTree, allowing you to use it to make purchases on Boom Learning.
To remove your card, simply click the red "Remove Card" button that appears once you have added a card. You can also replace your existing card using the "Change Card" button.