JSFiddle - React, Tailwind, and code Playground

HTML

<div>12345</div>
<button>обернуть</button>

CSS

span {color: red;}

JavaScript

$('button').on('click', function() {
	var text = $('div').html();
  var arr = text.split('');
  
  for ( var i = 0; i<arr.length; i++  ) {
  	 arr[i] =  "<span>" + arr[i] +  "</span>";
  }
  
  $('div').html(arr);
});