Are you listening on the port Railway provides?

For more information, take a look at https://docs.railway.app/guides/fixing-common-errors

It is an app developed with react using Vite, I am new to this and I do not know the port configuration, locally I use http://localhost:5172 because it is the url that the compiler tells me

Okay easiest fix will be to just create a service variable named PORT and set it to 5172

EDIT: Something to note, you're running a development server, I'd recommend copying the nixpacks.toml and Caddyfile from the following repo into yours https://github.com/brody192/vite-react-template, this will serve your app via Caddy which is more appropriate for production

funciona… gracias

no problem :)