Mobile Page – Collapsible events

[Al_Sin]

Hello,
I am creating mobile page only. The problem is : Events do not work in collapsible element for only mobile page. It is possible to set up events, but events never work.
The idea is to run simple JavaScript when customer opens collapsible. How it can be done?
For example, when I use script like:
var myPage = document.getElementsById("myPage");
myPage.addEventListener('click', function() {
alert('Hello world');
}, false)…
It works on click everywhere on the page except collapsible area.

Thank you,
Alexandre

[Pablo]

Mobile pages use jQuery mobile. The framework has its own set of events.
https://api.jquerymobile.com/1.4/collapsible/

Note that jQuery Mobile has not been updated since 2014 and is becoming obsolete.
I strongly recommend to build mobile websites with more modern functionality like layout gruid or flexbox.