It’s an AD12 1.5a with ground core and an L shaped power tip. There are a lot of near matches on Amazon and eBay. But genuine Casio adapters cost $41-$46. That’s a lot of money for a near match that may or may not work. Interestingly I tried a 9 v adapter from Casio, and it came on.
Looks like a standard 12v, 2A centre negative power supply. Loads on eBay for $15