‎NVMe SSD slot Generation compatibility?

I believe both slots are generation 3 because chapter 1 of the manual indicates that HP only offered Gen 3 NVMe SSD's in the model series and

Built with a PCI Express® Gen 4 x4 interface, 3D NAND flash, an 8-channel How do I install an SSD on my computer? Platform won't wake up from

candy palace slot slot supports PCIe Gen 4 x4 SSDs, while the right slot supports only PCIe Gen 3 x4 SSDs or SATA SSDs 0

can slot machines be controlled It does say PCI Express Version Supported: with