How can I enable playing local music from my NAS?

I've been using the Spotify subscription with the Flic button. But I'd like to cancel my subscription and play local music.

Flic plugin for GarageBand

With Flic and GarageBand, you can rapidly review your instrument or voice recordings with one button record and playback.

Download zip
Download source
Installation Instructions

The rapid rehearsal iteration:

1. Double-Click - Record.
2. Play instrument or sing.
3. Click - Playback
4. Listen
5. Repeat