Okay, in my case, the app works 'right'. The problem is the console doesn't shows the
console.log. I tried changing all features of the code and nothing (routes, directories...). If i use a
console.log with a random string in order to comprobe it (for example,
console.log('hello world')), and IT IS OUTSIDE of the export function, the console shows it; but if i put inside (which is the idea) doesn't show anything.