How to access music stored on a USB drive (SSD)

Hi gkkpch,
thank you very much for your reply! Ahh, I actually didn’t find that requirement when I searched - sorry for that. Sadly, it still does not work: I labeled the volume to issd, now the drive gets mounted to INTERNAL, instead of USB as before:

lsblk -f
NAME   FSTYPE   LABEL        UUID                                 FSAVAIL FSUSE% MOUNTPOINT
loop0  squashfs                                                         0   100% /static
sda                                                                              
|-sda1 vfat     boot         9CC8-09A7                              88.1M    48% /boot
|-sda2 ext4     volumio      eb55ffab-19d3-41c1-ba5a-6467611e98a1    1.3G    56% /imgpart
`-sda3 ext4     volumio_data 5150c78d-bb55-4219-a857-d922a8e325ff                
sdb                                                                              
`-sdb1 ext4     issd         2e583573-eac7-44c0-9aa2-451ac1ac606f  854.2G    48% /data/INTERNAL
or paste code here

I can access all my files via ssh, but the volumio gui still can’t find them. Is there e.g. a systemdlog that could help?
Thank you very much!