JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" id="button">click me</a>

JavaScript

var button = document.getElementById("button");
button.addEventListener("custom-event", function(e) {
    console.log("custom-event", e.detail);
});
button.addEventListener("click", function(e) {
    var event = new CustomEvent("custom-event", {'detail': {
        custom_info: 10,
        custom_property: 20
    }});
    this.dispatchEvent(event);
});