Can I buy a plan for more phone storage not iCloud storage
Can I buy more iPhone storage to download apps I already bought iCloud storage but it wasn’t right
iPhone 6s Plus, iOS 15
Question marked as
Your phone storage is “set” when your phone is manufactured.
You can’t add “storage” to your iOS device.
However, you MIGHT be able to use the “fixed” storage on your device more efficiently as outlined here:
Manage your photo and video storage - Apple Support