When you select this option upon checkout, you will be be prompted to enter your card information in a popup that looks like this:
Checking "Remember me" will prompt you to enter your phone number, so that you can receive a verification code confirming you want your information saved. This is a security precaution only for saved information, you do not have to complete this step if you leave "Remember me" unchecked.
When your purchase is successful, that pay button will turn into a green button with a checkmark. You will also receive both an email confirmation and a site notification telling you your chips were deposited.
IMPORTANT: If you happen to see a $1 authorization prior to the charges showing up on your bank statement, this is expected and entirely normal. Stripe does this authorization to verify that the card can indeed be used for the purchase. The authorization usually disappears within a couple of days.