Hi everyone !

I'm just a newbbie, studying a little bit of backend for a simple fullstack API, using MERN stack (React + Vite).
Everything works fine locally, event interactions with MongoDB Atlas.

My project structure is :

/backend

├── db

├── models

├── routes

├── .env

└── server.js

/frontend

├── public

├── src

├── components

├── App.css

├── index.css

├── App.jsx

├── main.jsx

├── Caddyfile

├── index.html

├── nixpacks.toml

├── postcss.config.js

├── tailwind.config.js

├── vite.config.js

├── .env

└── package.json

Both backend and frontend Railway services are deployed successfully.

Deploy logs for backend show connection to Mongo database is successful, but a warn mentions

npm WARN config production Use --omit=dev instead.

Deploy logs for frontend show "admin endpoint disabled" and "automatic HTTPS is completely disabled for server".

I have configured my frontend environment variable in Railway ("Settings" / "Variables" tag) to fetch queries with URL generated by Railway after backend deployment : VITE_BACKEND_URL = "https://... up.railway.app ".

I have tried

app.listen( PORT , "0.0.0.0" ,

( console.log (`Server listening on port ${PORT}`)) ) ;

in my backend "server.mjs" entry point file as indicated in link provided (https://docs.railway.app/guides/fixing-common-errors).

But are "mjs" extensions valid in Railway context ?

I have also tried to add "Caddyfile" and "nixpacks.toml" files found in this discussion , but I haven't modified anything for cors (as everything is fine locally).

Does anyone have suggestions or ideas please ?

Thank you.