We operate in both US and Canadian dollars based on your location. If your total is show in USD it will be billed in USD, and if your total is shown in CAD it will be billed in CAD. The same holds true if the total is shown in your local global currency, we will use this feature as much as Shopify supports it.
If you use a VPN the location settings might not work for you.
Your total at checkout will specify the currency you are paying, even if your location settings are not working.