@힙찔이닷컴 You should elaborate a bit more here and provide at least an error message - or better still, a detailed overview of what isn't working, or what results you got instead of what you expected.
Hi @javier-burón-garcía -- can't tell what the error is, since that's a generic Heroku error. Can you try running node app in Heroku console (I think it's called heroku run or something)?