JSFiddle - React, Tailwind, and code Playground

HTML

Date: <input type="text" id="startDate">
<select id="ddl">
  <option value="01">Volvo</option>
  <option value="02">Saab</option>
  <option value="03">Mercedes</option>
  <option value="04">Audi</option>
</select>

JavaScript

$(".ui-datepicker-month").prepend("<option value='' selected='selected'>Month</option>");
$(".ui-datepicker-year").prepend("<option value='' selected='selected'>Year</option>");
$('#startDate').datepicker({
            changeMonth: true,
            changeYear: true,
            onChangeMonthYear: function (year, month) {
                $("#startYear").val('#ddl');
                $("#startMonth").val(month);
            }
        });