Whilst your card works via direct debits, your card cannot be used for paying other direct debits as it is not a bank account therefore you cannot earn American Airlines AAdvantage® miles on your existing direct debits.
Your AAdvantage® Debit Card works by making transactions with the card directly, and then we collect the funds for each transaction via a direct debit from your linked bank account 2-3 working days later.
Any other direct debits you have (e.g., bills, subscriptions, services, etc) will continue to be paid directly from the bank account you set them up with.