Curcy pricing and compatibility

Hello,

I am interested in the Curcy currency converter plugin.

Questions:

-the price of 32 dollars, is that a one time payment, or do I pay 32 dollars every year (like a subscription)?

-is the Curcy plugin compatible with Stripe for Woocommerce plugin https://woocommerce.com/document/stripe/ ?

-if it is compatible with stripe, will I be using the Stripe keys (publishable key, secret key, webhook secret) to connect the Curcy currency converter to stripe?

-is the Curcy plugin compatible with Storefront Woocommerce theme?