Does the IKEA ALPSTUGA work with HomeKit, Alexa, and Google Home?
The ALPSTUGA speaks Matter over Thread.
For app control you need a Thread border router and a Matter controller, such as the DIRIGERA hub. It is a USB-C powered air quality sensor that measures CO2, PM2.5, temperature and humidity. It suits Home Assistant users, with native support through Matter over Thread. HomeKit, Google Home, Alexa and SmartThings users reach it through an integration (Matter over Thread).
How the device gets into the platform on this route. The headline is the best route: local before cloud, direct before bridged, core before community. The methodology page lists every level.