Where do I add ShieldConfiguration ?

I am creating a custom shield UI for when an app is blocked. have an AppDelegate file where my @UIApplicationMain is run

I pasted in the ShieldConfiguration code from the WWDC21 Meet Screen Time demo inside my app:

class MyShieldConfiguration: ShieldConfigurationDataSource {
    override func configuration(shielding application: Application) -> ShieldConfiguration {
        return ShieldConfiguration(
            title: ShieldConfiguration.Label(text: "Doxo", color: UIColor.blue),
            subtitle: ShieldConfiguration.Label(text: "heyhey")
            
        )
    }
}

but after calling store.shield.applications = .... the default restricted screen is being shown instead of the one I configured above

Where am I supposed to put MyShieldConfiguration ?