JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
  This is some text that should not be selectable!
</div>

CSS

.noselect {
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

JavaScript

var container = document.getElementById("container");
container.className += " noselect";