How do I purchase more iCloud storage for my iPhone 12?

An iPhone's internal storage isn't upgradable. If you're referring to iCloud+ space, click here and follow the instructions; this is a rental, not a purchase, and will be billed monthly.

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Go to Settings > [Your Name] > iCloud > Manage Storage > Buy More Storage, then choose a plan and confirm the purchase using your Apple ID.

Yes. Update it from a computer if possible.

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