you buy a cheap adapter to plug a m.2 nvme drive into a pci card and vice-versa (why? m.2 slots have ACS support for pci passthrough) they're essentially just

you buy a cheap adapter to plug a m.2 nvme drive into a pci card and vice-versa (why? m.2 slots have ACS support for pci passthrough) they're essentially just a wire as it's the same bus