Continue to Spotify DJ! Next is Beatsource DJ! Introducing how to get started with Beatsource

Support ended on July 1, 2020, but Spotify DJ at djay, which had been used for a while, has finally ended!
Which service will come next to the big favorite of streaming DJ Spotify?
What is the "Beat source" that is currently the most promising candidate?
How can I use Beatsource with rekordbox, Serato and djay?
And so on!