PM1061 (SATA III to Mini PCIe 2.0 adapter) - M-FACTORS Storage
Amazon.com: KALEA-INFORMATIQUE PCIe 2.0 x4 Controller Board for M2 SSD PCIe and/OR Sata - with 12V and 3.3V Support - 1 Port for M.2 SATA + 1 Port for M.2 PCIe! : Electronics
Amazon.com: M.2 PCIe PCI E Adapter, M.2 to PCI E3.0 X1 Expansion Card,M2 SSD NGFF NVME (m Key) to PCIe 3.0 x 1 Adapter with Low Profile Bracket for Desktop PCI Express
StarTech.com SATA PCIe Card 2 Port PCIe SATA Expansion Card 6Gbps SATA PCI Express to SATA Adapter Non RAID PCIe to SATA Converter SATA III 6Gbps PCIe 2.0 x1 card - Office Depot
Testing PCIe on the Raspberry Pi 5 | Jeff Geerling