If the payment by card has failed it is most probably due to the fact that you have not introduced properly the security code. It can also be because your bank or card do not meet the security requirements of our payment platform.
If the payment fails a second time, we recommend you try paying with PayPal. This option is compatible even if you do not have a PayPal account by using the guest session. If you ever find issues in paying with PayPal, we recommend you directly contact them. In this way, they will be able to go through the transaction and identify the problem.