Can't donate

Hi,

I would like to donate but upon filling out all the required fields, I get a message that says "card not confirmed".

I don't even know what this applies to.

I am asking for instruction on what went wrong and what to do to actually successfully donate.

Update - just received a reply from Paymentwall. They are no longer accepting cards from Serbia, for whatever reason. They pointed me towards Mint. However, I can buy 10 US dollars on Mint, and I need to pay 10 EUR here to donate which is only slightly more. So, I'd need to buy 20 $ on Mint only to pay 10 EUR here, correct? Not exactly compatible.

Ne mogu ni preko mobilnog da uplatim,bas nas mrze..