DynamoDB Session State in ASP.NET MVC

I have create a new ASP.NET MVC 5 Project. I have installed through Nuget the AWS SDK for .NET and Session Provider and I have read this article in Amazon: Article

I have this configuration in the Web.Config

 <sessionState
  mode="Custom"
  customProvider="DynamoDBSessionStoreProvider">
  <providers>
    <add name="DynamoDBSessionStoreProvider"
      type="Amazon.SessionProvider.DynamoDBSessionStateStore, AWS.SessionProvider"
      AWSProfileName="default"
      Table="ASP.NET_SessionState"
      Region="eu-west-1"
      />
  </providers>
</sessionState>

I run the web app using the IIS Express and all works fine (I can login and logoff), but if I access to my DynamoDB I don't have any item in the table ASP.NET_SessionState.

It's working like the custom state provider is ignored...

What am I doing wrong?

Thanks!!