PCIe Gen3 x2 USB 3.2 / 3.1 Card ASM3142- PCI Express to 4-Port Type C HUB Internal Expansion Card Controller Adapter PCI Express Card Desktop PC Support Multiple INs - Newegg.com
Lenovo 00UP681 - 256GB M.2 PCIe NVMe 2242 Gen3x2 Solid State SSD - CPU Medics
Vantec Thermal Technologies UGT-M2670 M.2 PCIe Gen3x2 B Plus M Key to 5 Ports SATA III Expansion Card - Walmart.com
I harvested a PCIe Gen3 x2 NVMe 1.3 SSD from my older laptop, the problem is that its length is short. I've held it in place with some tape, it should hold.