I'm trying to pay an existing recipient. Why am I being asked to use my card reader?
This could be because you have amended the reference for the payment you are trying to make. It isn't mandatory to add a new reference every time you make a payment to an existing recipient. The reference field is there so that the recipient and yourself are reminded of what the payment is for when they receive it. If the reference isn't required for the payment you wish to make, the previous reference you used can remain the same, which means you may not need to use the card reader to make your payment.