JSFiddle - React, Tailwind, and code Playground

HTML

<div contenteditable=true>123123123123</div>

JavaScript

var node = document.querySelector("div");
node.focus();
var caret = 10; // insert caret after the 10th character
var range = document.createRange();
range.setStart(node,caret);
range.setEnd(node,caret);
var sel = window.getSelection();
sel.removeAllRanges();
sel.addRange(range);