Smart buttons not working

[ipsalinguo]

Hi all,

I inserted smart buttons on my website, then had friends try to make a payment (set to 1-5c you choose from a combo box) on a test page but they do not seem to work. The transaction is not allowed but it seems to me that the code and settings are right.  Is payment allowed only within the EU or elsewhere? Are there any restrictions in place I do not know of?
Here is my test page(s):

https://ipsalingua.com/articolo-1/pagamento-cell.html (from cell phones)
https://ipsalingua.com/articolo-1/pagamento-pc.html (from pc/tablets)

Thanks in advance for your kind help.