Heroku deploy api not working

[akbarbin]

I have deploy in the heroku but the https://limitless-mountain-87107.herokuapp.com:3001/api/comments doesn't show json data.

How to run yarn start-dev in heroku?

Thanks

[yam-b]

Edit: Please ignore everything that was written here before, the answer was not complete and did not lead to a working model.

It's 4AM here, but I'm happy to say that I was able to set up a working heroku app! I used this guide to do the ERN part of MERN, this guide to do the M part of MERN, this guide to deploy. I will write a more concise tutorial on my own blog, but the bits and pieces (and mostly failing) here at mernCommentBox really helped me. Happy coding!