JSFiddle - React, Tailwind, and code Playground

HTML

<button id="btn">uninit</button>

JavaScript

window.addEventListener("DOMContentLoaded", (event) => {
  Init();
  AddEventListeners();
});

function Init() {
  let btn = document.getElementById("btn");
  btn.innerText = BUTTON_TEXT["inited"];
}

function AddEventListeners() {
  let btn = document.getElementById("btn");
  for (const [key, value] of Object.entries(EVENTS)) {
    console.log(`Add listener: ${value} for ${key}`);
    btn.addEventListener(key, value);
  }
}

const EVENTS = {
  "click": (event) => {
    console.log("on"+ event.type);
  },
};

const BUTTON_TEXT = {
  "inited": "come on",
};