JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<select name="" id="from">
  <option value="DPS">Denpasar</option>
  <option value="BGK">Bangkok</option>
  <option value="MOS">Moscow</option>
</select>

<select name="" id="to">
  <option value="DPS">Denpasar</option>
  <option value="BGK">Bangkok</option>
  <option value="MOS">Moscow</option>
</select>

kota tujuan: <div id="tujuan"></div>

JavaScript

$("#to").val("BGK");

var fromCity = "";
var toCity = "";
$('#from,#to').change(function(){
  var fromCityVal = $("#from").val();
  var toCityVal = $("#to").val();
  if (fromCityVal == toCityVal){
    alert("city of origin may not be the same as the destination city!");
  } else {
    //here's problem, what should I do?
    $("#from").val();
    
    var tujuanVal = $('#to').val();
    var innerText = $('select#to option[value="'+ tujuanVal +'"]').text();
    $('#tujuan').text(innerText) // tambahin ini
  }
});