Force Currency at Checkout PrestaShop module

Improve your store usability
Your customer can visit your store in any of the defined currencies at your store so they do not have to convert currencies. They can visit your store in their local currency and they will feel more comfortable. When they get to checkout, if customer has a different currency that the ones allowed, it will be automatically changed to the one that you selected so payment will be available only in one of these currencies.

Have more currencies than your payment method allows
You do not need to have available payment methods for each currency. You can have different currencies at your store so customers can shop with their preferred one but only some of them available at checkout.