Open iOS app from Safari after downloaded

Question

How do you configure your app to open from safari after it has already been downloaded? In the screenshot below when clicking "Open" it opens the app in the App Store, even after the app is downloaded.

I've implemented continue userActivity in the appDelegate class:

func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([UIUserActivityRestoring]?) -> Void) -> Bool {
        
        if let url = userActivity.webpageURL {
            self.continueWithLink(url: url)
        }
        
        return true
    }

What else do I need to do to make it function properly?