You authenticate each request by presenting your API key in the request header.

Authorization: Bearer {API_KEY}

For example, the beginning of a request using a fictitious key:

curl \
  -H 'Authorization: Bearer 476d901b4-a264a79-9db9-96d3dfaafb732'

The examples in the Guides assume that you have set an environment variable apikey, e.g.

export apikey=476d901b4-a264a79-9db9-96d3dfaafb732

You also need to set baseurl, see the Environments section for more details.