Set up iCloud Drive on iPhone
Use the Files app to store files and folders in iCloud Drive. You can access them from all your devices where you’re signed in with the same Apple ID. Any changes you make appear on all your devices set up with iCloud Drive.
iCloud Drive is built into the Files app on devices with iOS 11, iPadOS 13, or later. You can also use iCloud Drive on Mac computers (OS X 10.10 or later) and PCs (iCloud for Windows 7 or later). Storage limits depend on your iCloud storage plan.
Turn on iCloud Drive
Go to Settings > [your name] > iCloud, then turn on iCloud Drive.
Choose which apps use iCloud Drive
Go to Settings > [your name] > iCloud, then turn each of apps listed under iCloud Drive on or off.
Browse iCloud Drive
Tap Browse at the bottom of the screen.
Under Locations, tap iCloud Drive.
If you don’t see Locations, tap Browse again. If you don’t see iCloud Drive under Locations, tap Locations.
To open a folder, tap it.