Deeplink to app OR a fallback page that is not the app store


I’m trying to use app cards to deeplink into my app if it’s installed. If it’s not, take the user to a website landing page instead. The landing page provides the content that was shared and afterward prompts the user to download the app from the store. So far I’ve only been able to manage two behaviors. It goes to the landing page always (deeplinks don’t work as they would in the mobile web), or it deeplinks when the app is installed and it goes to the store if not.