Sync order on another status

functions.php

<?php
add_action('woocommerce_order_status_changed', array($this, 'redlight_custom_update_woocommerce_order_status'), 10, 3);
/**
 * @snippet       WooCommerce - Fortnox plugin by Redlight Media - Sync order on "on-hold"
 * @author        Redlight Media AB / Christopher Hedqvist
 * @compatible    WooCommerce 3.7.0
 */
public function redlight_custom_update_woocommerce_order_status($order_id, $old_status, $new_status) {
    if ('on-hold' == $new_status):
        // cCheck if this order should be created as offer
        $isOffer = Obj_Fortnox_Offer::check_is_order_offer($order_id);
        if($isOffer){
            $fortnoxOffer = Obj_Fortnox_Offer::get_instance();
            $fortnoxOffer->create_offer($order_id);
            $fortnoxOffer->create_offer_order($order_id);
        }else{
            // Create a normal order
            $fortnoxOrder = Obj_Fortnox_Order::get_instance();
            $fortnoxOrder->fortnox_order_completed($order_id);
        }
    endif;
}