Go into Settings → Multi-currency within the Chargebee Interface to set up your currencies. Choose your currency from 100+ currencies and get started with creating a plan.
The additional currencies that you've set up will appear for selection when you create your Plans/Addons/Coupons.
If you offer the same plan in various currencies, you need to create a plan for each of the currencies. This can be easily achieved using the 'Clone Plan' option.
To learn more about how multi-currency support works in Chargebee, here's our extensive documentation on setting up and managing your localized pricing within Chargebee.