You’ll need to create a bootable USB thumb drive using another Mac system. The issue you are facing is do to Apple upgrading the file system from HFS+ to APFS and to add to that Apple also altered the OS’s PCIe/NVMe driver between Sierra and High Sierra which is why the OWC drive won’t show up.
Here’s how to get the OS installers [https://support.apple.com/en-us/HT211683|How to download and install macOS]
And here’s the steps to convert it to be bootable once you copy it over to a GUID formatted USB thumb drive [https://support.apple.com/en-us/HT201372|Create a bootable installer for macOS]