Hooking into ajax_callback

What is the recommended method to hook into your ajax_callback function?
Simply put, once the content has successfully loaded, we need to trigger a javascript function.

The issue we are trying to resolve is explained in detail here:
https://wordpress.org/support/topic/always-expanded-when-displayed-with-ajax/

• This topic was modified 6 years, 3 months ago by twinpictures. Reason: added link to thread

The page I need help with: [log in to see the link]