JSFiddle - React, Tailwind, and code Playground

JavaScript

document.onkeyup = function(e) {

  if ((e.keyCode >= 65 && e.keyCode <= 90) ||
      (e.keyCode >= 97 && e.keyCode <= 122) ||
      (e.keyCode >= 48 && e.keyCode <= 57)){
      alert("Character/Number Pressed!");
  } else {
      alert("We don't care about this press because it's not a letter or number!");
  }
}