How to deploy a MEVN app on heroku?

Question

Heroku

Faced the problem of deploying an application on the Mongo+Express+Vue stack on Heroku.
The test application from the documentation deploys without problems. My application is divided into a client part and a server part.
When trying to deploy the client, an error occurs - the start script is missing. This script needs an index.js file with express installed in it. I copy this file from the documentation, make a commit and build, but nothing changes.
In short, my head is boiling again and I don’t know what to do)

Answer 1

heroku runs whatever you write in the "postinstall" and "start" commands in your package.json at the root of the project. Don't use "postinstall" yet, but later you can put the command "build vue production build" into it.
express is "installed" not in the index.js file, but in the same package.json.
If I understood correctly, you want to run two nodes in one heroku app? googled their price first in this case =))
If anything - write to tg @golden_dinar