What kind of working example are you looking for?
The page I link to in the WP Codex https://codex.www.ads-software.com/AJAX_in_Plugins give a pretty in-depth explanation of using AJAX in WP. The only real difference is that instead of using JQuery for the requests you use the scripts in this plugin. I think my documentation pretty well covers calling my script to make a requests.
I do plan at some point to put a basic tutorial together, but that requires time to kill which is something that is currently in short supply.
If you have specific questions on how to do something I will do my best to answer them.
Currently the best working example of this plugin being used is in one of my other plugins which can be found here: https://parasrch.jayaitch.com/