Missing 8 pin cable from Asus TUF Gaming PSU

As the title says, I bought this VGA: ASUS TUF Gaming Radeon RX 9070 OC Edition

and this PSU: TUF Gaming 1000W Gold | Power Supply Units | ASUS Global

The problem is i only get two 8 pin cables (6+2) i tried to power it on but the PC won't boot. My question is, how and where can i order a third 8 pin cable?