docs: added gift card documentation guides (#2939)

docs/content/advanced/ecommerce/handle-order-claim-event.md

@@ -28,7 +28,7 @@ Redis is required for batch jobs to work. Make sure you [install Redis](../../t
 
 ### Notification Provider
 
-To send an email or another type of notification method, you must have a notification provider installed or configured.
+To send an email or another type of notification method, you must have a notification provider installed or configured. You can either install an existing plugin or [create your own](../backend/notification/how-to-create-notification-provider.md).
 
 This document has an example using the [SendGrid](../../add-plugins/sendgrid.mdx) plugin.
 
@@ -47,26 +47,24 @@ You can learn more about subscribers in the [Subscribers](../backend/subscribers
 Create the file `src/subscribers/claim-order.ts` with the following content:
 
 ```ts title=src/subscribers/claim-order.ts
-import { EventBusService } from "@medusajs/medusa"
-
 type InjectedDependencies = {
-  eventBusService: EventBusService,
+  // TODO add necessary dependencies
 }
 
 class ClaimOrderSubscriber {
-  constructor({ eventBusService }: InjectedDependencies) {
-
+  constructor(container: InjectedDependencies) {
+    // TODO subscribe to event
   }
 }
 
 export default ClaimOrderSubscriber
 ```
 
-If you want to add any other dependencies, you can add them to the `InjectedDependencies` type.
+You’ll be adding in the next step the necessary dependencies to the subscriber.
 
-:::tip
+:::info
 
-You can learn more about dependency injection in [this documentation](../backend/dependency-container/index.md).
+You can learn more about [dependency injection](../backend/dependency-container/index.md) in this documentation.
 
 :::
 
@@ -74,29 +72,59 @@ You can learn more about dependency injection in [this documentation](../backend
 
 ## Step 2: Subscribe to the Event
 
-In the subscriber you created, add the following in the `constructor`:
+In this step, you’ll subscribe to the `order-update-token.created` event to send the customer a notification about their order edit.
+
+There are two ways to do this:
+
+### Method 1: Using the NotificationService
+
+If the notification provider you’re using already implements the logic to handle this event, you can subscribe to the event using the `NotificationService`:
 
 ```ts title=src/subscribers/claim-order.ts
+import { NotificationService } from "@medusajs/medusa"
+
+type InjectedDependencies = {
+  notificationService: NotificationService
+}
+
+class ClaimOrderSubscriber {
+  constructor({ notificationService }: InjectedDependencies) {
+    notificationService.subscribe(
+      "order-update-token.created", 
+      "<NOTIFICATION_PROVIDER_IDENTIFIER>"
+    )
+  }
+}
+
+export default ClaimOrderSubscriber
+```
+
+Where `<NOTIFICATION_PROVIDER_IDENTIFIER>` is the identifier for your notification provider.
+
+:::info
+
+You can learn more about handling events with the Notification Service using [this documentation](../backend/notification/how-to-create-notification-provider.md).
+
+:::
+
+### Method 2: Using the EventBusService
+
+If the notification provider you’re using isn’t configured to handle this event, or you want to implement some other custom logic, you can subscribe to the event using the `EventBusService`:
+
+```ts title=src/subscribers/claim-order.ts
+import { EventBusService } from "@medusajs/medusa"
+
+type InjectedDependencies = {
+  eventBusService: EventBusService
+}
+
 class ClaimOrderSubscriber {
   constructor({ eventBusService }: InjectedDependencies) {
     eventBusService.subscribe(
-      "order-update-token.created",
+      "order-update-token.created", 
       this.handleRequestClaimOrder
     )
   }
-  // ...
-}
-```
-
-You use the `eventBusService` to subscribe to the `order-update-token.created` event. You pass the method `handleRequestClaimOrder` as a handler to that event. You’ll create this method in the next step.
-
-## Step 3: Create Event Handler
-
-In the subscriber, add a new method `handleRequestClaimOrder`:
-
-```ts title=src/subscribers/claim-order.ts
-class ClaimOrderSubscriber {
-  // ...
 
   handleRequestClaimOrder = async (data) => {
     // TODO: handle event
@@ -106,6 +134,8 @@ class ClaimOrderSubscriber {
 export default ClaimOrderSubscriber
 ```
 
+When using this method, you’ll have to handle the logic of sending the confirmation email to the customer inside the handler function, which in this case is `handleRequestClaimOrder`.
+
 The `handleRequestClaimOrder` event receives a `data` object as a parameter. This object holds the following properties:
 
 1. `old_email`: The email associated with the orders.