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

PCIe vs : How To Pick An NVMe SSD nvme gen 4 in gen 3 slot The motherboard supports one Gen4 and one Gen3 slot, so I am interested in the possibility of either Interfaces Your suggestions are welcome nvme slot vs m2 Kinda odd he spent nearly 4 minutes talking about the difference between Gen 3 and Gen 4

nvme in pcie slot BUT you go buy the off brand no name cheaper 1TB Gen 4 NVME for lets say, 70$ (6-7K read