How to view all files on the Umbrel?

I tried using the file browser app (File Browser | Umbrel App Store) but it can only access an empty downloads folder, which doesn’t even have permissions to create files/folders in. Yes I made sure the account has Admin perms. I get 403 Forbidden errors.

Is there a way for me to view the root directory? Everything stored on the Umbrel?
I want to be able to easily access the folders I will use for Jellyfin so I can add my music and some movies. Do I need to give file-browser elevated permissions?
Or can I create and manage directories from the terminal?

I am also having another problem in Jellyfin itself where it can’t create any new folders when choosing a folder for a library.