If this laptop had 10.13+ installed on the old SSD, then you will need to boot from a macOS 10.13+ installer (necessary since only 10.13+ has the necessary NVMe driver) and erase the new SSD as GUID partition and APFS (top option) (or maybe MacOS Extended (Journaled) ). To use a third party PCIe SSD on a Mac that computer must already have had macOS 10.13+ installed before the swap (cloning isn't good enough) so that the system firmware has been updated to recognize a PCIe NVMe SSD. Maybe someone else with experience might have an idea. Also Recovery Mode shows no firmware password has been registered. The nearest I figure there is some firmware block. The drive simply will not register with the startup manager. I tried downloading High Sierra and installing it, again, without success. I tried formatting it HFS Journalled and APFS without success. OWC USB-SATA drive lights up, but Disk Utility can't see the drive. I have an OWC USB-SATA case and tried connecting the drive while in recovery mode as one certified tech suggested. The clone appears successful, until I try to select Apple menu -> System Preferences -> Startup Disk, or use the Startup Manager to boot off it. I am not able to Carbon Copy Clone a bootable 10.13 or 10.14 onto the SSD. So we know it isn't a hardware problem with how I inserted the SSD. I am able to boot off an external hard drive and disk utility of 10.13 and 10.14 is able to see and format the internal drive I inserted. I am Apple Certified, though haven't worked at an authorized service center for a couple years. The Mac shipped new with 10.10, and the drive started failing.I backed up the data on the old drive and its backup boots fine. It would appear the MacBook AIr has some sort of firmware that is preventing me from finishing the swapout of an Apple SSD with a MemoryX SSD that is supposed to be compatible with it.

Macbook pro 2015 ssd replacement