JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" data-role="button" data-theme="a" id="expand">Find It</a>

<div data-role="collapsible-set" data-content-theme="d" id="set">

<div data-role="collapsible" id="set1" data-collapsed="true">
    <h3>Header 1</h3>
    <p>SOME CODE HERE</p>
</div>

<div data-role="collapsible" id="set2" data-collapsed="true">
    <h3>Header 2</h3>
    <p>SOME CODE HERE</p>
</div>

</div>

JavaScript

//$(document).on("pageinit", function() {
$().ready(function() {

    // the "a" should not be needed
    //$("a#expand").on("click", function() {
    $("#expand").on("click", function() {
        $("#set2").trigger( "expand" );
    });

});