Open Spotify
Start playing a song, album, or playlist
Tap the Shuffle icon
Turn Shuffle off so it is no longer highlighted
On mobile, the Shuffle icon is usually near the playback controls
On desktop, click the Shuffle button in the playback bar
If Shuffle is still on, check whether you are in a playlist or album and tap the icon again
If using Spotify Connect, make sure Shuffle is turned off on the device currently controlling playback