Why is there a payment error on our website and how can we fix it?

Hi,
when we tried to pay for an item on our own website (https://www.nuovoid.com/ ), an error occured.
Do you guys know why and what we can do to fix that?

This is the part of which the error occured.
As you can see in the picture, we’ve entered the address and the credit card number.
We have tried to use other payment methods, but the same error appeared.
Hope these information would help.