JSFiddle - React, Tailwind, and code Playground

HTML

<body></body>

JavaScript

// jQuery plugin. Called on a jQuery object, not directly.
jQuery.fn.simulateKeyPress = function(character) {
  // Internally calls jQuery.event.trigger
  // with arguments (Event, data, elem). That last arguments is very important!
  jQuery(this).trigger({ type: 'keypress', which: character.charCodeAt(0) });
};

jQuery(document).ready( function($) {
  // Bind event handler
  $( 'body' ).keypress( function(e) {
    alert( String.fromCharCode( e.which ) );
    console.log(e);
  });
  // Simulate the key press
  $( 'body' ).simulateKeyPress('x');
});