why call show()

Author: mikehoffms

microsoft-edge/progressive-web-apps-chromium/how-to/digital-goods-api.md

@@ -163,7 +163,7 @@ MDN:
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 ## Purchasing an item (`PaymentRequest` constructor and `show` method)
 
-After your products and details are displayed to the user, implement the purchase flow by using the Payment Request API.  To purchase an item, construct a request that contains the item details by using the `PaymentRequest` constructor, and then use the `show` method of the `PaymentRequest` object.
+After your products and details are displayed to the user, implement the purchase flow by using the Payment Request API.  To purchase an item, first construct a request that contains the item details by using the `PaymentRequest` constructor, and then use the `show` method of the `PaymentRequest` object to start the payment flow.
 
 When combined with the Digital Goods API, the only required input parameter for the `PaymentRequest` constructor is `methodData`.  In that parameter:
 * Use the `supportedMethods` member to identify Microsoft Store Billing as the payment method with the string `"https://store.microsoft.com/billing"`.