Yes, you can add a currency converter to your store by installing an app or enabling the country/region selector in your theme.
Some themes like the Dawn theme have a COUNTRY/REGION SELECTOR. It's in the footer section by default. Each country will display the currency that you have set up under Markets in the Admin.
Alternatively, you can use currency converter apps as they let you recommend the best country and language for your visitors based on their browser preferences and location. Here are some of our recommendations: