The only cloud service that Hubitat Elevation can control at this moment is IFTTT. However, if you have the 2nd gen WiFi adapters, you can control Kumo Cloud with Google Assistant. Therefore, one of your answers is to use Google Assistant Relay.
By using Rule Machine and choosing Google Assistant Relay as the speech device, you enter the phrase to control your device, and prefix that phrase with [CC]. The result is, Hubitat Elevation will be able to silently tell google assistant to control your Google compatible devices. Works amazing! I control several devices that are cloud only, and even though one of them is also they supported by IFTTT, the Google Assistant Relay is much faster and significantly more reliable.
However, why not just use IFTTT? Kumo Cloud is supported.