If you are based in Canada and have a local bank account, you will be paid in CAD. If you want to be paid in USD you would need to route the payments into a USD account. If you travel to the US frequently or do larger purchases in USD, a USD account could be handy, but mostly your local currency would be the most useful in Canada.
US guests looking will be presented with the listing in USD unless they actively change the currency. When I look at your listing, I get the prices in NOK, and it work this way for every currency throughout the globe.
Maybe you are mistaking the airbnb fee for an exchange fee ?