Source adding headless

Hello, i’m running a headless pi server with kodi installed and can’t seem to add videos from an external hdd to it. The webgui has no options to add sources and i can’t seem to wrap my head around the config files and how i would add videos on a hdd to the source list. I can not load up kodi’s gui and do it from there because i have no monitor to connect to. Any suggestions? Thanks.