Make Spotify API keys optional if a user just wants artists playlists

[blastbeng]

Is there an existing issue for this?

• [X] I have searched the existing issues

Expected feature

Since spotisub supports artist recommendation, that is not bound to a user account

In case a user just wants playlists created by artist recommendation, the login on spotify dev account should not be needed and spotisub can work without using an API key and secret from Spotify developer dashboard

Possible Solutions

Make API key not mandatory for artist recommendations Endpoint and scheduled job.

Context / Reason

Artist Recommendations

Code of Conduct

• [X] I agree to follow this project's Code of Conduct

[blastbeng]

WON'T DO

Spotify apis can't be called without a client key and client secret