As part of the cloud-to-cloud integration, we successfully integrated the Kidde Cloud with the SmartThings Cloud, and the end-to-end integration is functioning as expected. However, we are unable to link Alexa or Google Home through SmartThings, and the integration is not working as expected for these voice assistant platforms.
ST staff do not appear to be monitoring the forums. Since it deals with your cloud-to-cloud integration, you should reach out directly to ST through build@smartthings.com
I am no expert but, if your goal is to integrate Alexa and Google Home with Kidde, you should be doing that in Alexa and Google Home. That is, a direct connection with Kidde, rather than via SmartThings. I could be wrong.