Super helpful for a newbie!! Thank you.You don't put your card on a Magic Band.
NOTHING is stored on the bands. They are merely keys to access your MDE account. EVERYTHING is stored in your MDE account, including a credit/debit card number. You can add or change your card information on the My Profile section of the MDE app. Once you've done that the MagicBand will be able to access the card info from your account.
Steve