// create alert div
const alert_box = document.createElement("div")
alert_box.innerText = "Not allowed!";
alert_box.className = "alert";
//get the parrent of where u wanna insert
const cont = document.querySelector(".container");
// get the element you wanna insert before
const prof = document.getElementById("profile");
// do the insert
cont.insertBefore(alert_box, prof);// The Node.insertBefore() method inserts a node before a
// reference node as a child of a specified parent node.
let insertedNode = parentNode.insertBefore(newNode, referenceNode)<div id="parentElement">
<span id="childElement">foo bar</span>
</div>
<script>
// Create a new, plain <span> element
let sp1 = document.createElement("span")
// Get the reference element
let sp2 = document.getElementById("childElement")
// Get the parent element
let parentDiv = sp2.parentNode
// Insert the new element into before sp2
parentDiv.insertBefore(sp1, sp2)
</script>
<div id="parentElement">
<span id="childElement">foo bar</span>
</div>
<script>
// Create a new, plain <span> element
let sp1 = document.createElement("span")
// Get the reference element
let sp2 = document.getElementById("childElement")
// Get the parent element
let parentDiv = sp2.parentNode
// Insert the new element into before sp2
parentDiv.insertBefore(sp1, sp2)
</script>