8-pin PCI-E

I need a 10-pin cable for my PSU that will split to connect to an 8-pin PCI Express power plug for the GPU and an 8-pin (4+4) for the CPU. The GPU Requires a specific 8-PIN PCI E plug (page 10 of the GPU User Guide). I can't find this cable for the life of me. My GPU is a GeForce RTX 2060...