JSFiddle - React, Tailwind, and code Playground

HTML

<div class="link_menu" id="foo">
        Menu software
  </div>
  <div class="menu" id="menu_left">
    <ul class="test">
      <li class ="test1">
        <a href="#">test1</a>
      </li>
      <li class ="test2">
        <a href="#">test2</a>
      </li>
    </ul>
   </div>

JavaScript

function cachemontre(id) {
    x=document.getElementById(id);
    if(x.style.display==""){x.style.display="block"};
    if (x.style.display=="none") {x.style.display="block" ; }
    else {x.style.display="none" ;}
}

document.getElementById('foo').onclick= function(){
cachemontre('menu_left')}