Update sheet.mdx (#1495)

Author: GameSquatch

docs/sheet.mdx

@@ -45,7 +45,7 @@ void main() async {
 
 Use your [test mode](https://stripe.com/docs/keys#obtain-api-keys) keys while you test and develop, and your [live mode](https://stripe.com/docs/keys#test-live-modes) keys when you publish your app.
 
-## 2. Add an enpoint [Server Side]
+## 2. Add an endpoint [Server Side]
 
 First, you need a Stripe account. [Register now](https://dashboard.stripe.com/register).
 
@@ -100,11 +100,14 @@ Future<void> initPaymentSheet() async {
           customerEphemeralKeySecret: data['ephemeralKey'],
           customerId: data['customer'],
           // Extra options
-          testEnv: true,
-          applePay: true,
-          googlePay: true,
+          applePay: const PaymentSheetApplePay(
+            merchantCountryCode: 'US',
+          ),
+          googlePay: const PaymentSheetGooglePay(
+            merchantCountryCode: 'US',
+            testEnv: true,
+          ),
           style: ThemeMode.dark,
-          merchantCountryCode: 'DE',
         ),
       );
       setState(() {
@@ -189,7 +192,7 @@ Make sure to set your Apple merchant ID `Stripe.merchantIdentifier` when you ini
 ```
 
 
-then add `applePay: PaymentSheetApplePay()`  with your  and the country code of your business.
+then add `applePay: PaymentSheetApplePay()`  with the country code of your business.
 
 ```dart
 Stripe.instance.initPaymentSheet(
@@ -234,15 +237,17 @@ For more details, see Google Pay’s Set up Google Pay API for Android.
 
 #### Add Google Pay
 
-To add Google Pay to your integration, set `googlePay: true` with your Google Pay environment (production or test) and the country code of your business.
+To add Google Pay to your integration, set `googlePay: PaymentSheetGooglePay()` and specify the country code of your business within that.
 
 ```dart
 Stripe.instance.initPaymentSheet(
   paymentSheetParameters: SetupPaymentSheetParameters(
     merchantDisplayName: 'Flutter Stripe Store Demo',
     //...
-    testEnv: true,
-    merchantCountryCode: "US",
+    googlePay: const PaymentSheetGooglePay(
+      merchantCountryCode: 'US',
+      testEnv: true,
+    ),
   ),
 );
 ```