Before You Use Optimize

Before you can use Optimize for website testing, you must install the Client API library (which is a JS file) to your web server and arrange for all pages you want to control to invoke the JS script.

The Client API (CAPI) library
The Client API is a JavaScript file that must be installed on your website's server. The API enables Optimize to make the necessary changes to site elements for testing Variations. If you are able to log into Optimize, then the Client API is installed.
JavaScript link
Every page that Optimize modifies must have an include link to the CAPI JS file. Typically, your Account Manager has already tagged the pages before you see them. Contact your Account Manager to confirm the installation.
Your Account Manager provides you credentials via email. If you forget or lose your credentials, contact your Account Manager.