How to install the license key?
If you are using any latest version of 4.2 and up, then simply upload the license.pem file you got from email@example.com in Web UI / Web Safety / License as indicated on the following screenshot. The information about your license will be displayed on the screen.
If you are using version 4.0 then please enter the license number from this file into Web UI / Support / License page and click Save Changes button as indicated on the following screenshot.
If you are using version 3.4, please copy the license key file to /opt/qlproxy/etc folder on your server (replacing any other license.key that may exist).