It's a tad cumbersome, but it is a much better alternative than trying to get your US credit cards to play nicely with some Manx or Hungarian-based payment sites (I don't know where Warmane actually hosts those services, but the US CC companies are known to occasionally flag it as suspicious activity).
> Access Subway site, Find Gift Cards (link:
https://www.mysubwaycard.com/English/Purchase/Card)
> Choose the eGift method (not Mail)
https://i.imgur.com/r3OFCS1.jpg
> Fill out info for your American CC to use this friendly US-based franchise
> Calculate the exchange rate for the desired donation level (EUR> USD/CAD)
(google should suffice, as you'll want to round up to the nearest dollar anyway; in my below example, I was aiming for the 30+3 donation level, with an exchange rate at the time coming out to 30EUR=36.27USD or something like that)
> Submit your own email as the Recipient
> Come to Warmane site, choose Donate
> Select Subway Gift Card Option
> Retrieve the Gift Card email (you'll receive a total of about 4 emails form Subway for notifications and receipts, one has a link inside to "View My Card"); You want the one that looks like this:
https://i.imgur.com/ShY1fRL.png
> Enter 16-Digit Card Number, Enter PIN; Can be found on the page email sends you to, looks like this:
https://i.imgur.com/wIZVoOn.png
Badda Bing, Badda boom, you're set with coins, and probably a few cents left over on that card (that I just forget about). Check exchange rates at the time of your purchase, and round up a dollar or three (depending on the size of the purchase, better safe than sorry).
Should also work just fine with $CAD in place of $USD.
