3.1 Purchase a PRO License
To license your installed Free compiler, you can rerun the installer until you get to the Licensing Information screen and then Click to purchase a PRO license. The link will direct you to the MPLAB® XC Compilers web page. Under the Licenses section, you can click on the View Licensing Options button to be directed to the Licenses web page. There you can find the PRO license that is right for you and then find a link to purchase it.
Note: Standard licenses are no longer sold. However, they are still supported.