Hello. I am trying to display banner ads but it does not show on my app. I followed the guide on https://developer.amazon.com/docs/mobile-ads/mb-quick-start.html . The only thing I din't add was the Banner Ads through Java Code, because it says that "To retrieve and display a banner ad, you will use an instance of AdLayout, which can be created either in code or XML ". I only used the XML.