I have a TP-Link Archer VR1600V that I connect the extender too, with no problem connecting to the internet. At the moment I only have one device connected through the extender as it does not have it'

How do I transfer files to my HDD that is connected to my modem’s USB. I can see the HDD in VLC. At the moment there are no files on the drive. I would like to know how I can send files to it from my