After successful installation of cPanel , you will receive a 15-day free trial to ensure cPanel software features and functionality meets their needs. The trial license will automatically expire after 15-days of successful installation. some times even after you buy the license it keep showing the Trail license Message:
Trial License This copy of cPanelWHM is for trial use and will expire at the end of the trial period. You will need to upgrade to a paid copy of cPanel & WHM to continue using the software after that period.
don’t worry , it can be solve by using a simple commend ,
Then run the following commend :
Its done .