Allow apps to use iCloud Drive
Some apps and websites can use your information on iCloud Drive to provide you with services and features. For example, an app might use the information on iCloud Drive to access files on your desktop.
To authorize an app or a website to use iCloud Drive, click OK in the dialog. If you don’t want to authorize the use of iCloud Drive, click Don’t Allow.
If you allow third-party apps or websites to use iCloud Drive, any information they collect is governed by their terms and privacy policies. It’s recommended that you learn about the privacy practices of those parties.
You can review and change your privacy settings using the Privacy pane of Security & Privacy preferences.
Choose Apple menu > System Preferences, click Security & Privacy, then click Privacy.