Subscription is paid from your iTunes account at the time of purchase with automatic renewal every 7 days.

If you did not sign up for this one-week subscription before, you will be offered a 3-day free trial period. The auto-renewal and write-off of money for a new period occurs during 24 hours immediately before the subscription expires.
Any unused part of the free trial period will be canceled when the user buys a subscription.

Prices in different countries can vary, and actual payments can be converted into your local currency depending on the country of residence.