Why you don’t have example codes for all widgets in Node.js??
Any help for the Menu Widget Please??
Probably due to resource limitations… feel free to contribute 
Blynk NodeJS seems more a pet project then an official support, so more user efforts required to figure out the syntaxes required.
But otherwise, searching for NodeJS on this forum will show various examples and snippets … of which you can use to try and get the menu to work.