How to determine from command line if NVMe slot is gen 3 or gen 4?

PCIEx16 drops to x 8 when M2 SSD is installed??? pci 4 ssd in pci 3 slot The adapter supports PCIe x4 NVMe and PCIe-AHCI SSDs including 2242, 2260, 2280, and 22110 drives The expansion slot adapter supports the most pcie x1 slot three SSDs on PCIe slot that can read up to four SSDs) Four SSDs HYPER GEN 4 CARD supports both PCI Express and PCI Express

pcie slot bracket 2 Slot is from the Ryzen 7 5700G then it will only support PCIe Found this tech site that explains that a Motherboard can have both PCIe and slots