CommBilling currently supports billing exclusively in Euros (EUR) as it is tailored for businesses operating within EU countries. This means that all invoices and credit notes generated through CommBilling will be issued in Euros, regardless of the customer's location or preferred currency.
If you receive orders in other currencies, Shopify will handle the conversion at the checkout stage. The converted amount will then be reflected in Euros on the invoices and credit notes generated by CommBilling. Please ensure your store settings on Shopify are configured to handle currency conversions if you deal with customers outside the Eurozone.
For more detailed assistance with multi-currency settings on Shopify, please refer to Shopify's official support documentation or contact their support team.