If you were able to click on the pay button, it means that all the necessary information was filled in on our side.
The blocking is certainly due to the authentication request from your bank, you are certainly making a false manipulation with the code that you received on your application or by SMS. You should contact your bank if you do not understand why the authentication is not working.
If the blocking occurs when you click on the "pay" button after having entered your card numbers, it may be that the CVC has not been entered.
This number must be indicated just to the right of the validity dates of your card.
If the problem persists, check if you have entered the correct card numbers.
If the problem persists, send us a request via the contact form.
Please attach screenshots, otherwise we will not be able to help you.