You might be able to see if your device's own app can connect to whatever voice service you're using (Samsung's Bixby, or Google Assistant). Or if that app has its own voice commands. Might need to grant microphone permissions.
Otherwise, either that app, or the voice assistants, might need to be connected to whatever device system you'd like to use (Samsung's Smart Things, or Google Home, are the main two I know of). From there, Bixby or Google Assistant might be able to anchor in & thus obey voice commands.
Again, I'm not fully sure how each works, but those are settings you can poke around in & see if you can figure out.