MacBook Pro 13" Early2015will not recognize OWC 480 SSD sent by iFixit

Yep, a common issue! But don't blame iFixit or even OWC here!

The issue you are facing is one of macOS generations, Apple made a massive change between Sierra and High Sierra within the file system as well as the PCIe/NVMe hardware and OS drivers. OWC or any other 3rd party SSD requires the system be running High Sierra to gain access to the new hardware and OS API services.

So you'll need to build a bootable macOS High Sierra or newer external drive like a thumb drive so you can upgrade your system to the needed macOS version. The built-in recovery won't get you to the needed version as it wants to stick with what you have and Apple had issues with their servers which still appear to be broken. Which is why I prefer just manually managing the OS.