You need a Homey app for Kogeek devices, which hasn’t been made yet (as far as I can see).
You would then connect directly to the devices through either Wifi or BLE (which hasn’t been enabled in Homey yet) to manage them with Homey. But until there’s an app there’s probably no way to add these devices to Homey.
I’ve been playing with the idea of creating a “HomeKit client” app, one that would act as the Home app does on iOS, and provide the ability to manage any HomeKit devices that it can find.
There’s a Node.js module called hap-client that can be used to implement such an app, but it won’t be exactly trivial to get it up and running on Homey since it relies on a few native modules that need to be crosscompiled before they can run on Homey.
If I have a bit more time, I intend to look further into it, but right now, to answer your question: you’re not missing something obvious, this functionality just isn’t available on Homey (yet).
I’ve installed “HomeyKit”-app and “Virtual Devices”-app and installed a Mode-Virtual-Device - called “Movement”.
HomeyKit presents the device virtual-device-“Movement” to Homekit and it shows up in my mobile Home-app.
In the mobile Home-app i’ve made an automation that whenever my camera detects movement it turn-on the “Movement”-virtual-device.
In a Homey-flow i turn on a lamp whenever the “Movement”-virtual-device is turned on.
I would certainly like to see a HomeKit client app for Homey. I don’t know if it would help you but apparently this capability is possible with Home-Assistant. Perhaps reviewing the code for its implementation may provide some helpful pointers.