Editing Files on R7000 ReadyShare Using ReadyCloud App on Android Device

I have an R7000 wifi router at home and have a USB drive connected and shared via ReadyCloud.  When I am working remotely, I can access the files and edit them and save the edits on my Windows 10 laptop.  However, When I use the ReadyCloud app on my Android phone, I can either open the files or download them locally and open them.  If I download them, I can edit the local copy, but I can't figure out how to upload the edited version of the file back to the ReadyShare drive.