Fail to deploy CRA app

Hello, I’m trying to deploy a create-react-app that I migrated from Heroku. (Turboku)

First time the app worked. But now that I try to create a new deploy it always fails

I have this in my fly.toml

  builder = "heroku/buildpacks:20"

  app = "/app/bin/boot"

I get :

2022-11-14T20:28:20Z   [info]Preparing to run: `launcher /app/bin/boot` as heroku
2022-11-14T20:28:20Z   [info]bash: /app/bin/boot: No such file or directory

I tried changing to “app/bin/boot”, “bin/boot” but same No such file or directory error.

Any ideas why is not working, specially if in the first migration worked?