Where is New Relic API key?
- Sign in to the New Relic user interface.
- Select (account name) > Account settings > Integrations > Data sharing > API access.
- Click Enable API Access, and then make a note of your API key.
Above is copied from https://newrelic.com/docs/features/getting-started-with-the-new-relic-rest-api
Update 20-Mar-2019
With new version of New Relic
- From the account dropdown in the New Relic UI, select Accountsettings > Integrations > API keys.
- Select Regenerate REST API key.
- Select (Show key) to view your account's new REST API key.
- Copy your account's REST API key to use with New Relic's REST API.
Hussain