Touch the file you want to send to iCloud for a while in the Local tab or swipe to the left and select More.
Select Export in the menu created.
If you select Export to this location, the concerned file will be uploaded in the iCloud account conntected to the device.
Select More(…) in the upper right corner of the Local tab.
Select Import in the menu created.
Select a file you would like to download in the file list of the iCloud account connected to the device.
The file will be saved in Local.