JSFiddle - React, Tailwind, and code Playground

HTML

<select id='contractor_type'>
    <option value='1' class='volunteer'>Romania</option>
    <option value='2' class='volunteer1'>Slovakia</option>
    <option value='3' class='volunteer2'>Belgium</option>
    <option value='Other' class='volunteer3'>Other</option>
</select>
<input id="new_contractor_type" type="text" style="display:none;"/>

JavaScript

$('#contractor_type').live('change', function () {
    console.log($(this).val())
    if ($(this).val() == 'Other') {
       
        //Code to change select list into textbox here
        $('#new_contractor_type').show();
    }
    else
        $('#new_contractor_type').hide();
});