How Do I Get on a Spotify Playlist?

Spotify gives artists an easy way to pitch music for playlist consideration.

To be considered, your release date must be at least 3-weeks in the future (only possible with DistroKid's "Musician Plus" or "Ultimate" plans). 

Here's info from Spotify on how to pitch:
https://artists.spotify.com/blog/share-new-music-for-playlist-consideration

Here's an article that explains how Spotify's curators make decisions:
https://artists.spotify.com/blog/behind-the-playlists-r-and-b

Good luck!