There are two ways of doing this. One is by creating a manual alert in the search app on the License Master. The second one is through Monitoring Console.
I will write about the second way, which is straight forward instead of writing a search.
Login through Admin and open the monitoring console. Settings >> Monitoring Console
In the Monitoring Console , there is Settings Menu, under which there is Alerts Setup option.
It will enlist all DMC Alerts, one of them is DMC Alert - Total License Usage Near Daily Quota
Here, you can Edit the License quota in the Edit option and You can create an Email Alert notification in the Advanced Edit option.
Finally you enable the alert.
Please make sure you have a working email setup to send emails.
... View more