The process to enable currencies is straightforward, head over to Paddle Dashboard and click on Catalog > Products, and select the product you want to enable more currencies on by clicking View > Edit (under the Prices section) > Country specific pricing on Paddle Billing, or clicking Edit > Set Prices on Paddle Classic.
We would highly recommend you enable all the currencies we support. These prices will be displayed to your customers in their own currency when they attempt to check out and the Paddle checkout will automatically detect the user's preferred language and standard currency. On Paddle Billing, go to Business Account > Currencies and "select all" to enable automatic currency conversion. On Paddle Classic, simply select "all" on the product price page itself.