I want to purchase 50GB storage space. How should effect payment?
I want to purchase 50GB iCloud storage space. How is the payment effected?
iPhone 8
It is charged every month directly from the payment method on file for your Apple ID / iCloud account, or any iTunes gift card credit balance you may have on your account.
See here: Buy more iCloud storage - Apple Support
and here: Change, add, or remove Apple ID payment methods - Apple Support