JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
  <div id="name">
    
   </div>
</div>

CSS

#container {
  width: 100px;
  height: 100px;
  border-radius: 100px;
  background: #333;
}
#name {
  width: 100%;
  text-align: center;
  color: white;
  font-size: 28px;
  line-height: 100px;
}

JavaScript

var name = "John";
  var lastname = "Doe";
  var initials = name.charAt(0)+""+lastname.charAt(0);
  
	document.getElementById("name").innerHTML = initials;