JSFiddle - React, Tailwind, and code Playground
by Pavan Kumar
HTML
<select name="customer_id">
<option value="c1">customer1</option>
<option value="c2">customer2</option>
<option value="c3">customer3</option>
<option value="c4">customer4</option>
<option value="c5">customer5</option>
</select>
<input name = "customer" type="text" value="" id = "customer">
JavaScript
jQuery(function($){
var $idval = $('#customer');
$('select[name="customer_id"]').change(function(){
$idval.val($(this).val())
}).triggerHandler('change')
})