Your subscriptions are displayed individually on your Dashboard after you login to your CryptoMaxx account, located below your profile information. You can see each subscription labelled, with details including when the subscription started, when you last paid, your due date, and your time remaining on that subscription.
You can renew a subscription only within 5 days of it's expiry date. The grey area marked "Pay after X more days" will turn to a red button that will allow you to make the renewal payment.