How to migrate NSPersistentCloudKitContainer to App Group to access in Widget

I have shipped an app that utilizes Core Data in CloudKit viaNSPersistentCloudKitContainer. I now want to add a widget that can query for the current data to display. It's my understanding you need to migrate this to a new location available to a shared App Group. How do you do this?

container = NSPersistentCloudKitContainer(name: "AppName")

container.loadPersistentStores { description, error in
    //handle error
}

container.viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy

container.viewContext.automaticallyMergesChangesFromParent = true