JSFiddle - React, Tailwind, and code Playground

HTML

<div class="dropdownPanel">
    <select name="countryList" id="countryList">
        
        <option value="0" disabled selected>SELECT</option>
        <option value="mexico">Mexico</option>
        <option value="argentinia">Argentinia</option>
        <option value="brazil">Brazil</option>
        <option value="chile">Chile</option>
        <option value="mexico">Mexico</option>
        <option value="venezuela">Venezuela</option>
    </select>
    <button class="cancel">cancel</button>
    <button class="confirm">confirm</button>
</div>

<div class='modal' style='display: none;'>
    The Modal
</div>

JavaScript

$('.confirm').click( function() {
      var val = $("#countryList").val();
        if (val!=0) {
            $('.modal').show();
             // alert(val); //test
        }
        
    return false;
});