For reference it appears that you may also use the Tuya platform component for Koogeek devices.
I was setting up a Koogeek KLUP1 plug (switch+sensor) that stated it was not HomeKit compatible. I don’t have any kind of hub anyhow, but as I already had a free Tuya account and the app on my phone, I simply added the device using Tuya / Add Device and it was recognised immediately by Home Assistant.
The downside for now is that the Tuya platform does not currently support Sensor device types, so it’s only useful for the switch functionality.