Adding or updating payment methods for the Apple App Store is a bit of a hassle. This is because it is hidden either in the Apple ID account settings or in the App Store. Sometimes the payment method that has been set is often problematic even though the balance has been verified.
In the future Apple will change this. But more to users who subscribe to something maybe like Netflix, Disney+ Hotstar, YouTube Premium and many other subscription services.
Every month when it is time for the application to charge, if the payment is problematic the user is allowed to update or add a payment method directly from within the application. Meaning users no longer need to go to Apple ID settings or settings in the App Store.
When there is a monthly payment problem, the application will issue a message for the user to fix it immediately. This feature will be built-in in iOS 16.4 and iPadOS 16.4. But for users to enjoy it, the developers of each application must integrate the StoreKit framework that Apple provides into their respective applications.