var onLoad = function () {
console.log("fd")
const editor = document.querySelector('editor')
editor.addEventListener("input", function (evt) {
console.log(evt)
})
}
<html>
<body onload="onLoad">
<div class="containter">
<div id="editor" contenteditable="plaintext-only"></div>
</div>
</body>
</html>
.containter{
width: 600px;
height: 560px;
border: solid 1px #ccc
}
#editor{
width: 400px;
height: 200px;
border: solid 1px #ccc;
outline:none;
margin: 20px auto;
}