PC SN520 256GB M.2 2230 NVMe PCIe Gen3 x2 SSD Solid State Drive SDAPTUW-256G | eBay
Amazon.com: LINKUP - NVMe Enclosure M.2 SSD to USB C 10Gbps Adapter | Aluminum Case USB 3.1 Gen 2 (10 Gbps) to PCIe Gen3 x2 Bridge Chip | for Windows & Mac
KingSpec 512GB M.2 NVMe SSD, 2242 PCIe Gen3x2 Internal Solid State Drive for Laptop/Notebook (2242, 512GB)
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.
PX400 NVMe PCIe Gen 3 x2 SSD - GOODRAM
Solid State Drive SSD - Best Buy Shop
Patriot SCORCH M.2 2280 512GB PCI-Express 3.0 x2 with NVMe 1.2 Internal Solid State Drive (SSD) PS512GPM280SSDR - Newegg.com