Merge pull request #230435 from zhenlan/106320

Add a note that `IOptions<T>` shouldn't be used for dynamic configuration

Author: prmerger-automator[bot]

articles/azure-app-configuration/enable-dynamic-configuration-aspnet-core.md

@@ -187,7 +187,7 @@ A *sentinel key* is a key that you update after you complete the change of all o
     ```
     ---
 
-You've set up your app to use the [options pattern in ASP.NET Core](/aspnet/core/fundamentals/configuration/options) during the quickstart. When the underlying configuration of your app is updated from App Configuration, your strongly typed `Settings` object obtained via `IOptionsSnapshot<T>` is updated automatically.
+You've set up your app to use the [options pattern in ASP.NET Core](/aspnet/core/fundamentals/configuration/options) during the quickstart. When the underlying configuration of your app is updated from App Configuration, your strongly typed `Settings` object obtained via `IOptionsSnapshot<T>` is updated automatically. Note that you shouldn't use the `IOptions<T>` if dynamic configuration update is desired because it doesn't read configuration data after the app has started.
 
 ## Request-driven configuration refresh