We support both Client Side and Server Side tracking, so you'll need your Public Key or Private Key depending on which method you're implementing your User and Event tracking with Cloudmattr.
Find you API Keys
Go to your Workspace Setting by clicking on the top right corner menu, and clicking on Workspace Settings.
Whitelisting a Domain
In order to track and accept data using the Client Side library, you'll need to add your domain. This is to whitelist your domain and avoid spam data if your script was placed elsewhere.