I had a spare NVMe SSD lying around (a Western Digital's SN850x) and plenty of USB-C cables. All I needed to do was pick an enclosure that let's the SSD connect to my PC through a USB port.

If you're upgrading your SSD, you can turn your old one into a fully functioning external storage drive for your devices using a storage enclosure ...

Plus you’ll likely save a lot of money by DIYing your own external SSD. Large-capacity PCIe drives are available at surprisingly low prices.