When creating a New Relic account, the user will be provided with a license key, which must be linked to the server to be monitored.
To add a license, you must first log in via My Zone
control panel (with the ZoneID account which has the server service).
After accessing My Zone, click on Webhosting
then select the desired virtual server and navigate to Webserver
-> Main domain settings
-> modify
-> PHP extensions
In the next window, look for the New Relic
field, tick the box next to it, and add the key you received for the license to the line below it.
At the end of the process, click modify
in the bottom left corner to save the changes.