API vs Client ID?

I recently installed the Apply with LinkedIn plug in, and followed the link to LinkedIn https://www.linkedin.com/secure/developer to setup my API key.

After walking through the steps, under Authentication Keys, I was given a Client ID and a Client Secret. I tried using both of these as the API key but I was never able to get the button to appear in my job posting.

http://www.blackwellking.com/job/test-with-linkedin-button/

Is there another API key that I am missing?

https://ww.wp.xz.cn/plugins/apply-with-linkedin-buttons/