Add order state config options

Config/Source/OrderStateOptions.php

@@ -0,0 +1,34 @@
+<?php declare(strict_types=1);
+
+namespace Yireo\GoogleTagManager2\Config\Source;
+
+use Magento\Framework\Data\OptionSourceInterface;
+use Magento\Sales\Model\Order;
+
+class OrderStateOptions implements OptionSourceInterface
+{
+
+    public function toOptionArray()
+    {
+        $options = [];
+        foreach ($this->getStates() as $state) {
+            $options[] = ['value' => $state, 'label' => $state];
+        }
+
+        return $options;
+    }
+
+    private function getStates(): array
+    {
+        return [
+            Order::STATE_NEW,
+            Order::STATE_PAYMENT_REVIEW,
+            Order::STATE_PENDING_PAYMENT,
+            Order::STATE_PROCESSING,
+            Order::STATE_COMPLETE,
+            Order::STATE_CANCELED,
+            Order::STATE_CLOSED,
+            Order::STATE_HOLDED,
+        ];
+    }
+}