Within your account settings you'll be able to see details of any active subscriptions you may have and be able update your card details for any future payments. You can access your account settings from this link.
If you have an active Pickwatch Pro subscription here you will see the details of when it's due to expire or renew and also the option to turn on or off auto-renewal:
Manage Card Details
Clicking the 'Update' button will redirect you to Stripe where you can update your card details for any future payments: