If you are ordering via the Internet, and your card in International, use it as you would with any Internet Purchase. Your card company will have converted the US Dollars into your local currency when the next card statement arrives.
I have the same problem here. Is there any way to change the currency at the checkout? I want to upgrade Snagit to the 2019 version, but my Brazilian bank only accepts via the original currency when buying from the internet. As techsmith automatically converts to Brazilian real, my purchase is always rejected.