When the admin manually changes an order status from pending to processing payment, I would like to redirect this admin to an external website for completing an additional step. The customer should not be redirected at any stage, just the admin.
I have added this to my function.php, but nothing happens on status change:
function my_woocommerce_order_status_processing($order_id) {
header('Location: http://www.google.com');
}
add_action('woocommerce_order_status_processing', 'my_woocommerce_order_status_processing');
Please, how can I achieve this?