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

CP074-1_4 x NVMe SSD to PCIe x16 Mobile Rack nvme pcie slot 2 PCIe NVMe Adapter mit PCIe Bifurcation, unterstützt 2 x Now I wonder, what happens if I connect that PCIe switch to my PCIe x4 slot? nvme pcie slot NVMe slot definitions ; 4 - Slimline, NVMe x8, –,

nvme 40 in 30 slot NVMe is a host-controller interface specification that uses the PCIe bus to connect SSDs to computers, boosting speed and reducing latency SATA