The first time you open the LUCI Subscribe application after the installation, you will be prompted to fill in your Subscription code.
The * item is mandatory:

Subscription code: after purchasing the software, you received an email with your activation code. Please fill this code in this field to activate your software. And click the Sign In button.

NOTE: If you do not have a subscription yet, you can buy it at our shop at Technicadelarte.com