HTTP/1.1 404 Not Found Error - API Key/Header

[#1]

Receiving HTTP/1.1 404 Error when following directions in Apigee docs for passing API key in HTTP Header. (http://docs.apigee.com/tutorials/secure-calls-your-api-through-api-key-validation)

Added <APIKey ref="request.header.apikey"/> to "verify API key" in Develop tab of API proxy.

Used cURL to pass API key:

curl -v -H "apikey: XXXXX" http://XXXX.apigee.net/v1/XXXXX

Error:

< HTTP/1.1 404 Not Found