Use iCloud Drive on iPhone
Use the Files app to store files in iCloud Drive, which you can access from your other devices as well as your iPhone. You can also invite others to view and edit files in iCloud Drive by sending them a link to a file—you don’t need to send them a copy of the file.
iCloud Drive is built into the Files app on iOS devices (iOS 11 or later). You can also use iCloud Drive on Mac computers (OS X 10.10 or later) and PCs (iCloud for Windows 5 or later or Windows 7 or later). To access iCloud Drive, you must be signed in to iCloud using your Apple ID. Storage limits are subject to 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 the listed apps on or off.
Browse iCloud Drive
Tap Browse at the bottom of the screen, then tap Locations.
If you don’t see Locations, tap Browse again.
Under Locations, tap iCloud Drive.
If you don’t see iCloud Drive under Locations, tap Locations.
To open a folder, tap it.
Open a file in another app
Touch and hold a file in iCloud Drive.
Tap Share, then choose an option.