JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
  <body>
    <p>This example uses the addEventListener() method to attach a "select" event to an input element.</p>
    Select some text: <input type="text" value="Hello world!" id="myText">
    <hr/>  
    Select text from number and push Get Selection 
    <br/>
     <p id="demo">
        1234567890
    </p>
    <button id="getSelection">Get Selection</button>
    <button id="clearSelection">Clear Selection</button>
  </body>
</html>

JavaScript

document.querySelector("#getSelection").addEventListener("click", function(e) {
            var { target, text } = getSelectionTextAndContainerElement();
            
            //just for checking
            reselect(getPathFromElement(target), text);
        });
        
        document.querySelector("#clearSelection").addEventListener("click", function(e) {
           var highlightDiv = document.querySelector("#highlightDiv");
           
           if (typeof highlightDiv !== "undefined") {
           		var arr = [];
              var parentNode = highlightDiv.parentNode;
              debugger; 
              
           		while (parentNode.firstChild) {
              		var firstChild = parentNode.firstChild;
                            
                  if (firstChild.nodeType === 3) {
                  		arr.push(firstChild.nodeValue);
                  }
                  else {
              				arr.push(firstChild.firstChild.nodeValue);
                  }
		
    							parentNode.removeChild(firstChild);
              }
              
              parentNode.appendChild(document.createTextNode(arr.join("")));
           }
        });
        
        function getSelectionTextAndContainerElement() {
            var text;
            var containerElement = null;
            
            if (typeof window.getSelection !== "undefined") {
                var selection = window.getSelection();
        
                if (selection.rangeCount) {
                    var node = selection.getRangeAt(0).commonAncestorContainer;
                    containerElement = node.nodeType == 1 ? node : node.parentNode;
                    text = selection.toString();
                }
            } 
            else if (typeof document.selection !== "undefined" && document.selection.type !== "Control") {
                var textRange = document.selection.createRange();
                
                containerElement = textRange.parentElement();
               ...