You can exchange your Knight Cash certificates and transfer them to the Power Up Store through the Knight Cash menu at VIP Manager in Moradon Town.
How to exchange Knight Cash
- Go to VIP Manager in Moradon Town.
- Open the Knight Cash menu.
- Select the Knight Cash option that matches your certificate.
In the screenshot, the NPC is labeled [VIP Administrator] Julien. The menu offers Knight Cash(100 ea), Knight Cash(350 ea), Knight Cash(700 ea), Knight Cash(1000 ea), Knight Cash(2000 ea), Knight Cash(5000 ea), and Knight Cash(10000 ea).