JSFiddle - React, Tailwind, and code Playground

HTML

<body >
<div id="popup"> 
<div id="campaign-alert" style="display:none;">
<h1>show me </h1>
</div>
</div>
</body>

JavaScript

function remove_style(all)
{
    var i = all.length;
    var j, is_hidden;
    var attr =
        [
            'style'
        ];
    
    var attr_len = attr.length;
    
    j = attr_len;
    
    all.removeAttribute(attr[0]);
}

function showdiv()
{
    var all = document.getElementById('campaign-alert');
    remove_style(all);
}