Help with how cfhttpparam work.

This is what it says on the API Basics | KnowledgeOwl site. But it seemed that for it to work, the full URL look something like this.

https://app.knowledgeowl.com/api/head/category/5697c6a632131cd740bd3123.json?_authbykey=56a7d8c512331c4058361687&project…

So, this is my attempt in using cfhttpparam.

<cfhttp url="https://app.knowledgeowl.com/api/head/category/.json?" method="GET" >

  <cfhttpparam name="categoryID" value="c6a632131cd740bd3123">

  <cfhttpparam name="_authbykey" value="56a7d8c512331c4058361687">

  <cfhttpparam name="project_id" value="55c4ffd131231c527e294fe6">

</cfhttp>

Okay, so I got Error in custom script module error. Any suggestion is much appreciated.