How can I connect from React (frontend) app to backend node service?

I would like to send request from React to backend (node). How can I do it? Do i need to define route in node and create a new file in /node directory?

I cannot find any solutions. Could you help me understand how it works?

Tudo o que você precisa saber encontra-se aqui:

http://help.vtex.com/pt/topic/vtex-io

Mas creio que lá não tem essa informação que você precisa :(