Spotify supports OAuth 2.
Add the Spotify OAuth2 backend to your settings page:
SOCIAL_AUTH_AUTHENTICATION_BACKENDS = (
...
'social.backends.spotify.SpotifyOAuth2',
...
)
Fill App Key and App Secret values in the settings:
SOCIAL_AUTH_SPOTIFY_OAUTH2_KEY = ''
SOCIAL_AUTH_SPOTIFY_OAUTH2_SECRET = ''