var my_elem = document.getElementById('my_id');
var span = document.createElement('span');
span.innerHTML = '*';
span.className = 'asterisk';
my_elem.parentNode.insertBefore(span, my_elem);function insertBefore(newNode, existingNode) {
existingNode.parentNode.insertBefore(newNode, existingNode);
}// 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)// add without creating a new element
document.getElementById('my_id')
.insertAdjacentHTML('beforebegin', 'your_html_code');