To obtain your license number, you need to register your Reason Adapted license to a Propellerhead user account first. If you don't already have an account, you can create one here: https://www.propellerheads.se/userReg/
1. Log in to your account and click the "Reason Adapted" link to the right, in the "Register/Upgrade" section.
2. Select your product version (Reason Adapted Version 4 for Line 6) and click "Continue". You'll be prompted for your registration code - this is the code printed on the card supplied with the software.
3. Once you've entered your registration code, your license number will be sent to you in an email. Enter this number into the corresponding field during the final step of software installation along with your Name and Organization info.
You'll also be able to see your license number at any time if you log in to your Propellerhead Account and click the "Your Products" link at the top of the page.