Hello, I remember that in the old versions of volumio, when I looked at my library, it found the cover.jpg file embedded in the .flacs, however it doesn’t work anymore, has something been changed?
A separate image in the directory with the music files.
Named folder.jpg or cover.jpg (can be png also).
Keep it under 1 MB, I size mine to 500 x 500 px and jpg with quality 0f 10 (Photoshop).