add some addtional details

src/pages/[platform]/build-a-backend/data/customize-authz/public-data-access/index.mdx

@@ -114,7 +114,7 @@ do {
 
 ### Extend API Key Expiration
 
-If the API key has not expired, you can extend the expiration date by deploying your app again. The API key expiration date will be set to `expiresInDays` from the current date when the app is deployed. In the example below, the API key will expire 7 days from the last deployment.
+If the API key has not expired, you can extend the expiration date by deploying your app again. The API key expiration date will be set to `expiresInDays` days from the date when the app is deployed. In the example below, the API key will expire 7 days from the latest deployment.
 
 ```ts title="amplify/data/resource.ts"
 export const data = defineData({
@@ -156,6 +156,8 @@ const backend = defineBackend({
 // );
 ```
 
+A new API key will be created for your app.
+
 ## Add public authorization rule using Amazon Cognito identity pool's unauthenticated role
 
 You can also override the authorization provider. In the example below, `identityPool` is specified as the provider which allows you to use an "Unauthenticated Role" from the Cognito identity pool for public access instead of an API key. Your Auth resources defined in `amplify/auth/resource.ts` generates scoped down IAM policies for the "Unauthenticated role" in the Cognito identity pool automatically.