How to Upload the License Key
To upload the license.pem file into the application, open Admin UI/Proxy Settings and choose the License Key settings node.
Click the Import button and navigate to the license.pem file you got from email@example.com. Click OK and ensure the license properties shown in the dialog box make sense.
It is also possible to manually copy the license.pem file into C:\ProgramData\Diladele\WebProxy\2.4\etc folder replacing the license.pem that should be present there.
Finally do not forget to Save and Restart Web Filtering Proxy service in order for the changes to be applied.