How to add SonarQube licence key for
In the Marketplace, when you upgrade to an edition (Developer, Enterprise, Data Center Edition) you are prompted to enter your license key. (Global Administration > Marketplace)
Alternatively, if an edition is already installed, you should be able to visit the License Manger (Global Administration > Configuration> License Manager)
How to add New License keys to Sonarqube 6.7 .4 community Edition?