I tested and see that it doesn't work. The html of the page does not follow the expected html for dokuwiki. Instead, however, you can use the override branch, which you can install from the manual tab using this url:
https://github.com/turnermm/sectiontoggle/archive/override.zip
Unfortunately, you will have to include the open an close toggle macros on any page that you want to have toggles. See the description of this method on the section toggle plugin page:
https://www.dokuwiki.org/plugin:sectiontoggle#override