You need to boot a macOS 10.13+ installer since older versions of macOS don't have the necessary NVMe driver required for the third party SSD. Try booting into Internet Recovery Mode using Command + Option + R to attempt to boot into the online macOS 12.x Monterey installer.
Even better, I highly recommend creating a bootable macOS USB installer using the instructions in this Apple article while your laptop is still able to boot normally just in case something goes wrong using Internet Recovery Mode.
How to create a bootable installer for macOS - Apple Support
Did this drive ever work internally with this laptop? If so and you are using macOS 10.13+, then perhaps the SSD adapter is bad or incompatible (assuming an M.2 SSD). From reading these forums it seems like the Sintech adapter is the best most compatible SSD adapter. Also, not all SSDs are compatible with all computers.
FYI, if macOS 12.x Monterey has never been installed on this laptop before, then you will need to have an original Apple OEM SSD installed internally so that the Monterey installer is able to update the laptop's system firmware. Once the laptop's system firmware has been updated by the Monterey installer, then it will be possible to reinstall the NVMe SSD and install Monterey. Otherwise you will be stuck at using macOS 11.x Big Sur as the most recent OS.
