docs: added send invitation guide (#3994)

* docs: added send invitation guide

* eslint fixes

docs/content/modules/customers/backend/send-confirmation.md

@@ -17,10 +17,6 @@ This guide will explain how to create the subscriber and how to use SendGrid to
 
 ## Prerequisites
 
-### Medusa Backend
-
-It’s assumed you already have the Medusa backend installed. If not, you can either use the [create-medusa-app command](../../../create-medusa-app.mdx) to install different Medusa tools, including the backend, or [install the backend only](../../../development/backend/install.mdx).
-
 ### Event Bus Module
 
 The event bus module trigger the event to the listening subscribers. So, it’s required to have an event bus module installed and configured on your Medusa backend.
@@ -139,7 +135,7 @@ When using this method, you’ll have to handle the logic of sending the confirm
 
 ## Step 3: Handle the Event
 
-The `handleCustomerConfirmation` event receives a `data` object as a parameter. This object is the entire customer object. So, you can find in it fields like `first_name`, `last_name`, `email`, and more.
+The `handleCustomerConfirmation` method receives a `data` object as a parameter which is a payload emitted when the event was triggered. This object is the entire customer object. So, you can find in it fields like `first_name`, `last_name`, `email`, and more.
 
 In this method, you should typically send an email to the customer. You can place any content in the email, such as welcoming them to your store or thanking them for registering.