By default, Internet access via the Lock is allowed.
You can deny Internet access via the Lock by signing in as the admin user and choosing Settings > Advanced Settings.
By ticking the box “Prevent Internet access from LAN and SERVICE ports” you can block all devices accessing the Internet via the Lock.
Additionally, if you want to allow access to certain addresses, you can list allowed addresses one by one on the “Allowed Internet addresses that can be accessed from LAN” section.
Remember to save the settings.