add a folder to favourites in iCloud Drive

To add a folder to your Favorites in iCloud Drive on macOS, open Finder, navigate to iCloud Drive, locate the folder, and add it to your favorites. On iOS/iPadOS, access files and folders through the Files app. Favorites cannot be managed on iCloud.com, so use macOS or iOS/iPadOS for this functionality. For more information, contact Apple Support.

Drag the folder to the “Favorites” section in the Finder sidebar or right-click and select “Add to Sidebar.”