Storage
I recently upgraded my storage because I need a storage for a game but it’s saying that I don’t have enough storage even though I upgraded storage.
You can buy more iCloud virtual storage. But you cannot add additional iPhone physical storage. Virtual and physical storage are two completely different things and one cannot substitute for the other. For more info, see:
What's the difference between device storage and iCloud storage? - Apple Support
iCloud+ plans and pricing - Apple Support