Fortnox - Set PhoneNumber to both Phone1 and Phone2 fields in Fortnox

functions.php

<?php
/**
 * @snippet       WooCommerce -Fortnox - Set PhoneNumber to Phone2 field in Fortnox
 * @author        Redlight Media AB / Christopher Hedqvist
 * @compatible    WooCommerce 3.8.0
 */
function redlight_fortnox_order_both_phone_fields( $orderData, $order_id) {
    $order = new WC_Order($order_id);
    $orderData['Order']['Phone2'] = $order->get_billing_phone();
    
    return $orderData;
}
add_filter('obj_fortnox_order_data', 'redlight_fortnox_order_both_phone_fields', 10, 2 );