The license key file (lamaxu.lic) should be copied to the Lamaxu config directory. Whenever the license key is renewed, Lamaxu needs to be restarted in order to pick up the changes. You do not need to reinstall Lamaxu when upgrading from the trial to the commercial license.
When defining the name of the license key file name in the 'Admin' screen, do not use the full path or the file will not be detected.
On Windows
C:\Program Files (x86)\QueueMetrix\LAMAXU\config
On Linux
/opt/queuemetrix/lamaxu.{version}/config