Unable to get CMS lightbox to work by following video in post for new feature

Design help CMS
1

Hello, I am trying to follow the post for the new functionality for cms lightbox galleries.

Here is the post

Step one

  1. Place a lightbox straight into the design of a collection template page

Ensure to connect your image or video source to both the lightbox link and nested image.

Where the video shows the dropdown with the option image I see “no fields connected” I am trying to use a multi image field.

share link

Here is my public share link: LINK
(how to access public share link)