Use the SFTP Remove Directories action to delete a directory from the SFTP server. To delete a single file use SFTP Remove Files action.
SFTP connection
Enter the path to the directory to be removed on the remote server. Make sure the full path is included (specified from the user's home directory) as the SFTP protocol doesn't have the concept of a "current directory" like FTP does.
Specifies whether to remove directories recursively, i.e. including subdirectories