JSFiddle - React, Tailwind, and code Playground

HTML

<div class="content"></div>
<div class="toolTip" id="toolTip">
    <a href="#" id="button" class="btn btn-info saveText btn-xs copy" style="display:none;">Save Text</a>
</div>

CSS

div.content{
    border:1px solid red;
    height:50px;
}

JavaScript

$('.content').mouseenter(function(){
    $('#button').show();
});

$('#button').click(function(e) {
    $(this).hide();
});