Can’t get this to work using Elementor Pro

Another user was having the exact same issue as me a few years ago, but sadly, there was no response.

https://www.ads-software.com/support/topic/not-working-in-elementor-pro-2/

I can get Collapse-O-Matic to work if I put the entire code in a Text Editor widget, but if I want to build a page using Elementor it doesn’t seem to compute with the /expand shortcode (exact same problem in the above thread).

Any help would be appreciated.

I tried putting the collapse-o-matic code in the following widgets: shortcode, text editor, html.