Lutril needs a New Relic User API key to list users through NerdGraph, compare them against your directory, and (optionally) create or remove users. The key must be a User key, not a license or ingest key.
To create, update, or remove users the key owner needs the Authentication Domain Manager role
Setup steps
In New Relic, open the user menu (top right) and go to API keys. Open API keys
Click Create a key, choose User for the key type, give it a name, and click Save.
Copy the full key immediately. Only the first characters are shown afterward.
In Lutril, connect New Relic and paste the User API key.
Set the Region to eu if your New Relic account is in the EU data center, otherwise leave it as us. A US key only works on the US endpoint and vice versa.