Hi PatJ2014,
You will need to add the driver through HII. However, before it can be added to HII you will need to download and locate the correct driver. If you go to HII Driver Management on your core, and click "Build Library", the HII Driver Repository Manager window will open up. In this window, you will see the "Root UNC path where driver files are stored". Make sure you copy the correct driver to this path.
Alternatively, you can go to Tools -> Security and Compliance -> Patch and compliance, and then click the "Download Updates" button on the toolbar. The Download Updates wizard will open and you can select your particular brand of device if it is listed. The window is pretty self explanatory.
Whichever method you choose, once you have the correct drivers downloaded, go back to HII Driver Management and click on Build Library -> Save to build your driver library. Once built, the correct drivers can be referenced in your Provisioning Template under HII.