No music files available in Squeezebox player on iPad

Hi,

Hope one of you experienced guys will help a total beginner.
I have installed a piCorePlayer on a Raspberry pi 3 with a hifiberry digi + pro.
Have both Squeezelite and LMS running.

Installed the hifiberry card without problems.
Resized filesystem
Updated Squeezelite
Installed LMS
Installed additional filesystems
Installed USB disk and enabled and mounted it
Did not do anything in the 'Setup Network Disk Mount'

Am I missing anything?

In the iPad Squeezebox player 'Album artists', 'Albums' etc. says 'Empty'.
I am a total beginner in this, hope someone will take the time to help. Thanks!