Application does not run when deployed in Heroku

[Chessray]

I followed all the instructions here: https://kotlinlang.org/docs/js-react.html

However, instead of seeing the running application, the [website] displays an error.

Log excerpt:
2023-06-07T16:50:26.144957+00:00 heroku[router]: at=error code=H14 desc="No web processes running" method=GET path="/" host=shrouded-everglades-31155.herokuapp.com request_id=0828bb63-9d5b-49e0-a51e-9a20fab9e658 fwd="90.252.146.255" dyno= connect= service= status=503 bytes= protocol=https

Everything works fine when I run the application on my machine.