Background updates with the app closed

Hello everyone, I am spending a lot of work with an application, this is based on obtaining the information from the official USCIS website, the user enters their receipt and it verifies on the USCIS website if that receipt exists, once verified it returns the information of that receipt, which I save in coredata so that the user only has to press a button to reload that information, all this is perfect, the problem is that I want the cases to be updated in the background so that the user does not have to be Entering the application, it is responsible for updating only the cases and if there was a change in your case, showing a notification to the user, I have the function of updating the cases so that when it detects a change in the database it notifies the change to the user. user, I have read the documentation but Background Task, Fetch etc. does work for me if the application is in the background that is, not closed, but when it is closed completely it does not update these cases, I have read in groups and with silent notifications to lift the application but I don't want to depend on a server, is there a method to call the function to update the cases when the application is closed (SwiftUI - Swift for iOS I am programming)