Handle null values when creating shipment

readme.txt

@@ -2,8 +2,8 @@
 Plugin Name: Sendy
 Plugin URI: https://app.sendy.nl/
 Description: A WooCommerce plugin that connects your site to the Sendy platform
-Version: 3.1.1
-Stable tag: 3.1.1
+Version: 3.1.2
+Stable tag: 3.1.2
 License: MIT
 Author: Sendy
 Author URI: https://sendy.nl/
@@ -61,6 +61,9 @@ Hierop zijn onze [algemene voorwaarden](https://sendy.nl/algemene-voorwaarden/)
 
 == Changelog ==
 
+= 3.1.2 =
+* Fix an error when creating a shipment
+
 = 3.1.1 =
 * Fix an error message when synchronizing shipping methods
 

sendy.php

@@ -4,7 +4,7 @@
  * Plugin Name: Sendy
  * Plugin URI: https://app.sendy.nl/
  * Description: A WooCommerce plugin that connects your site to the Sendy platform
- * Version: 3.1.1
+ * Version: 3.1.2
  * Author: Sendy
  * Author URI: https://sendy.nl/
  * License: MIT

src/Modules/Orders/OrdersModule.php

@@ -112,7 +112,7 @@ protected function create_shipment_with_smart_rules(\WC_Order $order, bool $exec
             'reference' => $order->get_id(),
             'order_date' => $order->get_date_created()->format(\DateTimeInterface::RFC3339),
             'options' => [],
-            'shippingMethodId' => $shippingMethod->get_instance_id(),
+            'shippingMethodId' => $shippingMethod ? $shippingMethod->get_instance_id() : null,
         ];
 
         $this->addAddressToRequest($order, $request);

src/Plugin.php

@@ -17,7 +17,7 @@
 
 class Plugin
 {
-    public const VERSION = '3.1.1';
+    public const VERSION = '3.1.2';
 
     public const SETTINGS_ID = 'sendy';