JSFiddle - React, Tailwind, and code Playground

HTML

<select id="Codes" name="CODEOPTION">
    <option value="A">Option A</option>
    <option value="B">Option B</option>
    <option value="C">Option C</option>
    <option value="D">Option D</option>
</select>

<input type="text" name="CODES" value=""/>

JavaScript

$("#Codes").change(function(){
                   
                   var temp=$(this).val();
   $("input[name='CODES']").val(temp);                
});