First rule of home automation: “the model number matters.“ Different models offer different functionality, but the truth is none of them offer a lot at this time.
For safety reasons, you can’t turn any of the ovens on with Alexa, which is probably why you’re not getting any responses.
Exactly what you can do will sometimes be listed in the user manual for that specific model.
For example, for oven model NX60T8511SG/AA , you can use Alexa to set the temperature (but only after you’ve manually turned it on), ask if the oven is on, or turn it off. And that’s it. You can’t control any of the other features. See the voice control section in the user manual.
The same for any other Samsung appliance. Find the user manual, then check the voice control section to see exactly what you can do with it.
If the information isn’t in the user manual, then it may be in the app.
Also, this forum was set up many years ago so that customers could help other customers with smartthings Automation.
There is also an official Samsung support forum for the appliances and televisions which is staffed by employees, and you might get quicker answers there: