JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <section id="yt_menu" class="block" style="visibility:hidden">bubu</section>
</body>

JavaScript

function delayMenu() {
  tempoDelay = setTimeout(showM, 2000); // 2 segundos após a página ser carregada
}

function showM() {
  document.getElementById("yt_menu").style.visibility = "visible";
}
window.onload = delayMenu;