Dual GPUs for Precision 5820

Hello, I currently have a RTX 3070 and a Quadro p4000. I'm trying to set up both for virtualization, but there is only one 8+6 pin connector. I ordered a new cable, 10pin to 8+6pin but it doesn't power on. The PSU should support it since it can handle 950w

GinTai 10pin to 8pin+6pin PCIe GPU Power Connector Adapter

I've seen other threads on this topic but I'm not sure what pin layout would allow for this to work. I found another one on ebay with a different pin layout but not sure if this would be correct.

New 10pin to 8+6pin Power Cable for DELL Precision 5820 and GPU New USA | eBay

Thanks.