New hard drive isn't available 2013 air I purchased a new hard drive for my 2013 Macbook air from OWC. I've checked the hard drive seating, but the drive doesn't show up either in the Disk Utilities GUI or using diskutil list. Any other suggestions on how to get it to show up/mount?
If you power off and reset the NVRAM that would be the only software thing you could do to cause the system to rescan all the ports and rebuild the IO tree of connected devices.

Barring that working, you would need to go in and reseat all the cables and start replacing things one by one.


drive
cable between the board and the drive
connection / logic board


OWC has good support in my experience, so checking with them to confirm you’ve got the correct part - no firmware update needed on Mac or on the drive.

You could boot to an external USB drive in the mean time or boot to Recovery and reinstall High Sierra on an external drive so that you’re sure the Mac firmware is up to date 100%. Some imaging workflows might keep the EFI / firmware down level. A clean install from Apple’s installer while connected to the internet should solve any firmware update issues.