Defined railway.toml / railway.json file in sudirectory

My usecase is that I'm using monorepo where root path is the root of monorepo / and not sub-directory such as /workspaces/application as I need to have access to higher context.

I didn't find it in configuration however rather to check whether there is still way how to configure path of railway.toml / railway.json for example using env variable?
for some reason that configuration is a beta feature, you can do /beta here and then you will have access to the option to set the config path in the service settings