In the theme editor (Customize) => Section, click Header > Scroll to CURRENCY SELECTOR or LANGUAGE SELECTOR
You can enable multiple currencies by adding the countries and regions for each currency that you want to accept in your store.
1. In the Shopify Admin, navigate to Settings.
2. Choose Markets > Add Market.
3. Set group Name, select Add countries/ regions and select the countries/ regions you want.
4. and Save
