Order creation API endpoints updated for guest users (#6086)

* Order creation API endpoints updated for guest users

* Refactored docs Order creation API endpoints updated for guest users #6086

* Refactored order apis for guest-cart

* Refactored order apis for guest-cart

* Update order-add-items.md

* Update order-create-order.md

* Update order-create-order.md

* Update order-create-quote.md

* Update order-prepare-checkout.md

* Update order-add-items.md

Author: Sairam9519

src/guides/v2.2/rest/tutorials/orders/order-add-items.md

@@ -14,9 +14,12 @@ functional_areas:
   - Catalog
 ---
 
-This article shows how to add a simple product, a downloadable product, and a [bundle product](https://glossary.magento.com/bundle-product) to the cart.
+This step shows how to add a simple product, a downloadable product, and a [bundle product](https://glossary.magento.com/bundle-product) to the cart.
 
-All calls are performed on behalf of a customer, and the customer's token is specified in the [authorization](https://glossary.magento.com/authorization) header.
+These calls are performed on behalf of a customer, and the customer's token is specified in the [authorization](https://glossary.magento.com/authorization) header.
+
+{:.bs-callout-info}
+Use the `V1/guest-carts/<cartId>/items` endpoint to add items to the cart on behalf of a guest. Do not include an authorization token. The payload and response is same as the logged-in customer for all product types, except for from quote ID in the payload.
 
 ### Add a simple product to a cart {#add-simple}
 

src/guides/v2.2/rest/tutorials/orders/order-create-order.md

@@ -23,6 +23,9 @@ The [shopping cart](https://glossary.magento.com/shopping-cart) contains three i
 
 When you submit payment information, Magento creates an order and sends an order confirmation to the customer. Since we are using an offline [payment method](https://glossary.magento.com/payment-method) in this tutorial, we do not need to provide detailed payment information. The endpoint used in this example requires only the payment method and billing address information.
 
+{:.bs-callout-info}
+Use the `V1/guest-carts/<cartId>/payment-information` endpoint to set the payment information on behalf of a guest. Do not include an authorization token.
+
 **Endpoint:**
 
 `POST <host>/rest/<store_code>/V1/carts/mine/payment-information`

src/guides/v2.2/rest/tutorials/orders/order-create-quote.md

@@ -36,7 +36,10 @@ Magento identifies three types of users that can create a shopping cart:
 
 ### Create a cart for a logged-in customer {#create-cart}
 
-This tutorial manages the cart of a logged-in customer. Unless otherwise noted, all calls must specify customer's token `q0u66k8h42yaevtchv09uyy3y9gaj2ap` in the header.
+All calls for a logged in customer must specify customer's token `q0u66k8h42yaevtchv09uyy3y9gaj2ap` in the header.
+
+{:.bs-callout-info}
+Use the `V1/guest-carts` endpoint to create a cart on behalf of a guest. Do not include an authorization token. The `quoteId` for the guest customer quote will be masked.
 
 **Endpoint:**
 

src/guides/v2.2/rest/tutorials/orders/order-prepare-checkout.md

@@ -25,6 +25,9 @@ Now that all the items have been added to the cart, we can prepare the order for
 
 Magento calculates shipping costs for each shipping method that can be applied to the order. In this tutorial, the `flatrate` ($5 per item) and `tablerate` shipping methods are active.
 
+{:.bs-callout-info}
+Use the `V1/guest-carts/<cartId>/estimate-shipping-methods` endpoint to estimate shipping costs on behalf of a guest. Do not include an authorization token.
+
 **Endpoint:**
 
 `POST <host>/rest/<store_code>/V1/carts/mine/estimate-shipping-methods`
@@ -104,6 +107,9 @@ In this call, you specify the shipping and billing addresses, as well as the sel
 
 Magento returns a list of payment options and calculates the order totals.
 
+{:.bs-callout-info}
+Use the `V1/guest-carts/<cartId>/shipping-information` endpoint to set the billing and shipping information on behalf of a guest. Do not include an authorization token.
+
 **Endpoint:**
 
 `POST <host>/rest/<store_code>/V1/carts/mine/shipping-information`