How to execute php from button click

Do you have access to the class or id of the max button you are trying to hook up with the php script using AJAX?

One way of getting the id or class could be via Google’s dev tools by right clicking the button in chrome and selecting “Inspect”.

More information on dev tools can be found here: https://developer.chrome.com/devtools

If yes, then the link below may be useful. It shows you how to implement an ajax call given a class of a button.
http://wordpress.stackexchange.com/questions/24235/how-can-i-run-ajax-on-a-button-click-event

Not sure if you’ve already seen this Codex page : https://codex.ww.wp.xz.cn/AJAX_in_Plugins

Let me know how it works out.