Why can't I download tracks to a USB with my Beatsource streaming subscription?

Downloads are not included with any Beatsource subscriptions.

Beatsource subscriptions are streaming-focused, and with a Beatsource PRO+ subscription, you have access to an offline locker to store up to 1,000 tracks offline for use without WiFi.

If you want to download tracks, you can purchase individual tracks from the Beatsource store, but some content, such as DJ Edits/Remixes are streaming-only content, and cannot be purchased.