How to refer to specific dir. inside a different resource of the app ?

I am building an app consists of 2 different resources

1. Server App using “NestJs”
2. Web App using “Create React App”

Each on his own different repository on GitHub.

Usually I used to refer to the web “build” dir. from inside the server to serve it as a static dir. using a code like this

path.join(__dirname, '..', '..', 'build')

as in “Heroku” for example

Now. How can I do the same on digitalocean ? How can i refer to the “build” dir. inside the Web app resource from inside the server resource as i don’t know the dir. structure of the app ?

This is my typical response I get

{"statusCode":404,"message":"ENOENT: no such file or directory, stat '/workspace/build/index.html'"}