You need to first create a page in the faceted browse interface. Here’s the manual
I created a sample page in the “Pages” area, but when I try to add the page to the Faceted Browse pane it does not give me the option to add the page created. Also, the link provided does not work.
Updated link: Faceted Browse - Omeka S User Manual
I can’t reproduce the error. Are you positive that you saved the test page? What version of Omeka S and Faceted Browse are you using?