ICloud folder sharing was first announced as an iOS 13 feature. Apple has removed the feature to fix some bugs. IOS 13.4 has restored functionality. See how to use it on iOS, iPadOS and macOS.
Share iCloud folder
Share a folder
On the Mac, you can choose to send the invitation link via email, messages, a copied link or AirDrop. On iOS and iPadOS, you will see options for the other applications you have installed. You will see the sharing options that can be configured, such as who has access to the folder and their permission level.
You can share documents in the same way. Apple recently updated iWork, which allows you to place a Keynote, Numbers or Pages document in a shared folder and it will start sharing automatically.
Change sharing options
You can change sharing options for folders, but not for individual documents. So, if they are not already in a folder, put them in one.
The process is similar if you want to stop sharing a folder or document.