By default, Spotify restricts downloads to Wi-Fi to prevent data overages. If you have an unlimited data plan, you can enable this: Internet and data usage - Spotify Support
Click your profile name or the downward arrow in the top right corner and select Settings . Essential Spotify Download Settings to Configure download settings spotify
Tap your profile picture in the top left corner, then select Settings and privacy . By default, Spotify restricts downloads to Wi-Fi to
Improved clarity for standard headphones. download settings spotify