Steps to setup Preview mode for a Work

Login to the ACF Admin site, as an Administrator User
From the Main Page, click "ePub Books and Documents"
1. Click on "Spine" against the respective Title
2. The “Table of Content” interface will load.
3. Click to check/uncheck the sections you want/do not want to display in the Preview section.
Click “OK” to save the spine data to the server.