In that case, I would recommend voting on this feature request:
That thread and the Hubitat community thread it links to describe some of the challenges with trying to use Hubitat’s Lock Code Manager (LCM) for this. LCM is specifically designed for interfacing with Lock devices - the lock codes aren’t actually stored in LCM and there’s no API to interface with LCM (or for LCM to interface with anything other than a lock device).