Tooltip can be shown on Button hover and it can be achieved by setting title attribute.
The following snippets illustrates how to show tooltip on Button hover.
ej.base.enableRipple(true);
//To change the Button type.
var button = new ej.buttons.Button({ isPrimary: true, content: "Button" });
button.appendTo('#element');
button.element.setAttribute("title", "Primary Button");<!DOCTYPE html><html lang="en"><head>
<title>EJ2 Button</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="description" content="Typescript UI Controls">
<meta name="author" content="Syncfusion">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/styles/material.css" rel="stylesheet">
<link href="styles.css" rel="stylesheet">
<script src="https://cdn.syncfusion.com/ej2/21.2.3/dist/ej2.min.js" type="text/javascript"></script>
</head>
<body>
<div id="container">
<button id="element"></button>
</div>
<script>
var ele = document.getElementById('container');
if(ele) {
ele.style.visibility = "visible";
}
</script>
<script src="index.js" type="text/javascript"></script>
</body></html>#container {
visibility: hidden;
}
#loader {
color: #008cff;
height: 40px;
left: 45%;
position: absolute;
top: 45%;
width: 30%;
}