When installing an app, theme or when downloading phpFox you are asked to enter your sites site's License ID and Key. This information is emailed to you when you first purchase a license. If you have lost this information you can retrieve from here.
Access license key from web server
If you are running Neutron (v4 or higher) you can access your sites site's license information by opening the file /PF.Base/file/settings/license.sett.php.
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