How to store music on local SD card

I want to use the local SD card that volumio is installed on to store my music. a few guides here and there say i can do that, but nowhere will tell me how and ive looked for hours. i saw one post from 2015 mentioning a symlink, but how do i point to a directory when there isnt one to point to?

hello,
No need for such complicated things!
From a computer running on the same network than your volumio device, just browse your local network (with files explorer in Windows). If needed enter IP address of the device. You should see Volumio. Copy your files to yhe storage available.