How to use an USB-HDD for the Squeezeserver (LMS) Addon?

Hi!
I´m using the generic x86/64 Version of Home Assistant on a small Fujitsu Futro s740, J4105, 8GB.
Installing the LMS-addon to replace a dedicated Raspberry Pi -Server, was no problem, and it works like a charm. I just can´t get my USB-HDD to work, so I can´t play my ripped music instead of just streaming songs from Tidal and Spotify.
Can anybody explay what I can do?

Best regards

Dirk

The lms addon docs describe config for [mounts] which should do it.