The license comes with your Pioneer DJ gear is only compatible with rekordbox ver,. 5.
rekordbox ver. 6 released on 14 Apr, 2020 is the latest major update.
If your Pioneer DJ gear is a hardware unlock device, you no longer need a license.
Please see what features are available with your Pioneer DJ gear for free on attached URL.
If you have already subscribed to a Core or Creative plan, please refer to here for how to activate your plan.