@dbemowsk I'm sorry, I really don't know. I've never tried domoticz, not to mention any of its plugins.
I do have Alexa working with my system, but I don't like it, just because of sending recorded voice out of the house all the time. So I plan to replace it once I get time to get Rhasspy going, assuming that I can get it going well enough.
Alexa works very well with home assistant. Though we use a service that costs $5/month to be the cloud piece to interact with the Alexa service so that I don't have to get something standalone working here for that. Though I think that service is really only for integrating to home assistant, so it probably wouldn't do you any good. It's saved me a bunch of time, and as I want to use my time to replace the whole thing with Rhasspy, it's been worth it to me.
But part of the reason I mention all of that is that with a quick search, it looks like controlicz is a similar service. Although they do say that you need to add the skill to your Alexa account. That would be annoying to me - doesn't that mean you need to say something like "Alexa, ask controlicz to turn on the kitchen light" or whatever?? With Nabu Casa, it also just uses the built-in smart home skill, so you don't have to install anything extra, leaving those extra words out each time. After the 10th time of having to do it I bet I'd really be gritting my teeth!