Updated README how to add custom refund type

README.md

@@ -23,6 +23,77 @@
 📖 Full documentation is available here:
 👉 [Refund Plugin Documentation](https://docs.sylius.com/refund-plugin)
 
+## Customization
+
+### Adding Custom Refund Types
+
+If you need to add custom refund types (e.g., fees, commissions), you can extend the `RefundType` class:
+
+1. **Create your custom RefundType class:**
+
+```php
+<?php
+
+declare(strict_types=1);
+
+namespace App\Model;
+
+use Sylius\RefundPlugin\Model\RefundType as BaseRefundType;
+use Sylius\RefundPlugin\Model\RefundTypeInterface;
+
+class RefundType extends BaseRefundType implements RefundTypeInterface
+{
+    public const ORDER_FEES = 'commission';
+
+    public static function commission(): self
+    {
+        return new self(self::ORDER_FEES);
+    }
+}
+```
+
+2. **Create your custom Doctrine RefundEnumType:**
+
+```php
+<?php
+
+declare(strict_types=1);
+
+namespace App\Doctrine\Type;
+
+use App\Model\RefundType;
+use Sylius\RefundPlugin\Entity\Type\RefundEnumType as BaseRefundEnumType;
+use Sylius\RefundPlugin\Model\RefundTypeInterface;
+
+class RefundEnumType extends BaseRefundEnumType
+{
+    protected function createType(string $value): RefundTypeInterface
+    {
+        return new RefundType($value);
+    }
+}
+```
+
+3. **Configure your application to use the custom classes:**
+
+```yaml
+# config/packages/sylius_refund.yaml
+imports:
+    - { resource: "@SyliusRefundPlugin/config/parameters.php" }
+
+parameters:
+    sylius_refund.refund_type: App\Model\RefundType
+    sylius_refund.refund_enum_type: App\Doctrine\Type\RefundEnumType
+```
+
+4. **Clear the cache:**
+
+```bash
+php bin/console cache:clear
+```
+
+Now you can use your custom refund type in templates and business logic.
+
 ## Security issues
 
 If you think that you have found a security issue, please do not use the issue tracker and do not post it publicly.