Some information on using different types of content to make your own Yoto cards
What format can I use to make my own Yoto cards?
You can make Yoto cards with any content that you own that is in MP3 or AAC/M4A format.
Can I make cards from Audible content?
Can I make cards from Spotify content
Spotify is a streaming service, with a subscription payment model, so you can't download music in MP3 or AAC. There is not currently any support to play Spotify playlists on Yoto.