@claudia first thing first. Did you made a snowboy word ? then did you put the file in your MagicMirror folder ? Then did you put it in your configuration (you should probably delete their example since they didn’t provide the file to go with it. inside the config from the voicecontrol.js too).
Then when you say the word, is the module picking it up and send the associate notification ?
You can know if the notification is sended by runing the mirror in dev mode so you can see the console and use some module to print the notification they receive (I think some default module do it already).
When you got this part to work, you can proceed to the next step, which is catch the notification in the Iframe module