MyDigitalSSD has released a product that allows you to turn an M2 SSD with NVMe support into an external USB 3.1 drive.
There is a board with the JMicron JMS583 controller, which essentially converts the PCIe 3.1 x2 interface into a USB 3.1 Gen 2 interface. Cables that connect to USB Type-C and Type-A connectors are included in the kit. The buyer also receives a thermal interface that transfers heat from the SSD chips to the body made of metal, fasteners and a screwdriver. It costs 40 dollars.