Family Sharing Requires Credit Card
I have bought two iPad mini's for my children (both under 13) and am trying to set up an iCloud a/c for each in Family Sharing.
In iCloud 'Family Sharing' settings, it tells me that I need to 'verify that you are an adult by adding a Credit Card to your account in iTunes' because currently my account is linked to a Debit Card.
Can you tell me how to ADD a Credit Card to resolve this process, as I still wish to pay for purchases with my Debit Card.
iPhone 6, iOS 8