JSFiddle - React, Tailwind, and code Playground

HTML

<select id='SerK1'><option values="123">123</option><option values="1234">1234</option><option values="1235">1235</option></select>
<select id='SerK2'></select>

JavaScript

$(document).ready(function(){
$('#SerK2').html($('#SerK1').html());
});