Right now your store uses "CubeCart Lite" the free version of CubeCart which has restricted features and a limit of {$TRIAL_LIMITS.customers} customers or {$TRIAL_LIMITS.orders} orders (whichever comes first) and {$TRIAL_LIMITS.administrator} administrator. Below is our website showing our pricing and links to further information.
Please note that the software license key can be added in the "Advanced" tab of your stores General Settings.