I also would like to know this... and it seems no one reads the question...
A USB to NVMe adapter, or PCIe M.2 adapter... NOT a drive,
There are tons of drives out there, there are tons of SATA m.2 adapters, just none that I can find that can take an m.2 NVMe or PCIe SSD and be used externally, its the only reason I have not upgraded my laptops SSD yet, I want an external box to slap the 128gb into for cloning and just to have. I don't even really care about the speed either.