When you purchase a PandwaRF (Rogue Pro, Marauder Standard, …) with a Kaiju license, the PandwaRF is automatically registered into Kaiju. When you first request a Kaiju analysis from your PandwaRF, you will be requested to create or link a Kaiju account. The PandwaRF, the Kaiju license and your email will then be linked together.
Once this first association is done, you can use Kaiju without using your PandwaRF.
See Kaiju Account Creation for more details.