Configure an iCloud setting in Apple Business Essentials
The iCloud setting lets you restrict specific features of iCloud when a user signs in to their iCloud account.
iCloud settings are device specific; if you want the same iCloud configuration on a user’s iPhone and Mac, the iCloud settings need to be added to both devices.
Some iCloud services aren’t available for Managed Apple Accounts. See Customize user access to certain apps and services.
In Apple Business Essentials, sign in with a user who has the role of Administrator.
Select Settings
in the sidebar, then select All Settings.Select the Add button
next to iCloud 
.Under Platform, select the operating systems you would like to configure this setting for.
Choose whether to prevent the use of iCloud Keychain.
Choose any of the following to allow users with Mac computers that enroll in a device management service to use the following iCloud features:
Setting
Description
Calendar
Select to allow Calendars to sync with iCloud.
Contacts
Select to allow Contacts to sync with iCloud.
Desktop and Documents
Select to allow files from the Desktop and Documents folder to sync with iCloud.
Mail
Select to allow Mail to sync with iCloud.
Notes
Select to allow Notes to sync with iCloud.
Reminders
Select to allow Reminders to sync with iCloud.
Safari bookmarks
Select to allow Safari bookmarks to sync with iCloud.
Choose any of the following to allow users with iOS and iPadOS devices that enroll in a device management service to use the following iCloud features:
Setting
Description
Backup
Select to allow the device to backup to iCloud.
iCloud Drive
Select to allow files to sync with iCloud Drive.
Photo Library
Select to allow photos to sync with iCloud Photos.
Photo Sharing
Select to allow Shared Albums to be created with the Photos app.
Select Save.