A device is authorized automatically when you designate a playlist/album for offline use. Offline use is only available for the TIDAL mobile app.

You can download an album for offline use by clicking and holding on to the album cover and then selecting download. To download a track for offline use, click and hold the track name, then add it to My Collection. You can then visit the Tracks section in My Collection to download all of your favorite tracks by sliding the toggle over from gray to cyan.

You can read more about offline mode for Android and iOS.

 Click here to learn how to Deauthorize a Device