Use:

-f bestaudio 
-f ba --extract-audio --audio-format flac

for best audio quality.

-o "%(title)s.%(ext)s"

for correct naming of the files.

--add-metadata

for correct IDs.

--parse-metadata "playlist_index:%(track_number)s"

for parsing track numbers.

--embed-thumbnail

This instructs yt-dlp to embed the thumbnail image in the downloaded audio file.

You can use youtube URLS to download complete album in one go:

#yt-dlp -f bestaudio -o "%(title)s.%(ext)s" --add-metadata  --parse-metadata "playlist_index:%(track_number)s"  https://www.youtube.com/playlist?list=OLAK5uy_nBJgNLqUL8A64tQMKFNPK3x7KzNOgfbUw

Embed thumbnail in opus music files

#ffmpeg -i audio_file.opus -i thumbnail.jpg -c:v mjpeg -c:a copy -metadata:s:v title="Album Art" output_file.opus