JSFiddle - React, Tailwind, and code Playground
HTML
<input id=firstname type=text>
<select id="name" name="name" multiselect>
<option value="">Please select...</option>
<option value="India">India</option>
<option value="Us">Us</option>
<option value="China">China</option>
</select>
JavaScript
$(document).ready(function() {
$("#name").on("change", function() {
$("#firstname").val($("#name").val());
})
});