JSFiddle - React, Tailwind, and code Playground

HTML

<input id="textbox">

JavaScript

document.getElementById('textbox').onkeypress =
function(e){
  var c = e.which || e.keyCode;
  if((c > 31 && c < 65) || (c > 90 && c < 97) ||
     (c > 122 && c !== 127))
    return false;
};