Please refer to this code. It works fine.
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>TextEditor - jQuery EasyUI</title>
<link rel="stylesheet" type="text/css" href="https://www.jeasyui.com/easyui/themes/default/easyui.css">
<link rel="stylesheet" type="text/css" href="https://www.jeasyui.com/easyui/texteditor/texteditor.css">
<script type="text/javascript" src="https://www.jeasyui.com/easyui/jquery.min.js"></script>
<script type="text/javascript" src="https://www.jeasyui.com/easyui/jquery.easyui.min.js"></script>
<script type="text/javascript" src="https://www.jeasyui.com/easyui/texteditor/jquery.texteditor.js"></script>
</head>
<body>
<div class="easyui-window" style="width:600px;height:400px">
<div id="td" class="easyui-texteditor" title="TextEditor" fit="true">
<h3 style="text-align:center">TextEditor</h3>
<p style="text-align:center">TextEditor is a lightweight html5 editor based on EasyUI. It is completely customizable to fit your needs.</p>
</div>
</div>
</body>
</html>