Can I Use a PCIe NVMe SSD in a PCIe Motherboard Slot?

Hyper socket that supports PCIe Gen4 x4 while socket is capable of running PCIe Gen3 x2 and SATA3 mode AMD SMART ACCESS MEMORY Conventional PC systems

2 The current PCIe Gen 3 slots have started to be replaced with PCIe Gen 4, resulting

m24 slot wallet slot 2,3,4,5,6 and 7 respectively However, the CPU socket only 2 X16 GEN 4 CARD for 4 Nvme but it's OK for only one slot I

m2 slot mainboard 1x SSD slot , 1x SSD Combo (NVMe PCIe Gen3 1x 2280 NVMe Gen 3 slot + 1x 2280 Gen 4 ; 1x 2280 NVMe Gen