Connecting Alexa to Spotify requires a premium/paid account. Other than that, Alexa Spotify integration is not yet available globally. So, if you find Spotify absent, it is likely because your amazon account is registered outside the United States.
Play Music
“Alexa, play Spotify”
“Alexa, play with {artist} from Spotify”. Example: “Alexa, play with The Doors from Spotify”
“Alexa, play {tittle} by {artist} from Spotify”. Example: “Alexa, play Easy On Me by Adele from Spotify”
“Alexa, play the album {title} by {artist} from Spotify”. Example: “Alexa, play the album Best 4 You by Maroon 5 from Spotify”
“Alexa, shuffle the playlist {artist} from Spotify”. Example: “Alexa, shuffle the playlist Mariah Carey from Spotify”
Playback
“Alexa, next song”
“Alexa, pause”
“Alexa, play”
“Alexa, resume”
“Alexa, turn up the volume”
“Alexa, turn down the volume”
“Alexa, set the volume to {number}”. Example: “Alexa, set the volume to five“
Set Alarms
“Alexa, wake me up at {time} a.m./p.m. to {artist}”. Example: “Alexa, wake me up at 7:00 a.m. to Taylor Swift“
“Alexa, wake me up at {time} a.m./p.m. the playlist {album}”. Example: “Alexa, wake me up at 7:00 a.m. the playlist Morning Jazz“
“Alexa, wake me up at {time} a.m./p.m. to {title} by {artist}”. Example: “Alexa, wake me up at 7:00 a.m. to Best Song Ever by One Direction“