how can I use iCloud with encrypted files?

Create a file in finder > iCloud Drive , right click on file and click on get info , open the pad lock by entering admin password and check the box of locked ( for a single file ) , if there are multiple files create a folder in finder > iCloud Drive and drag and drop all the files inside it again check the box of locked and and then follow the section - Apply permissions to all items in a folder or a disk .( a small lock will be created on the folder with files inside it ) .

in the article https://support.apple.com/en-in/guide/mac-help/mchlp1203/10.15/mac/10.15

https://support.apple.com/en-bh/guide/mac-help/mchlp1342/mac

See >>> https://support.apple.com/en-ca/HT202303