What do the deploy logs show? Looks like the app failed to deploy correctly. Are you able to show the logs?

It displays correctly, but I don't know what the error is.

Make sure the port your application is listening to is the same port your URL is mapped to.

How can I check that?

Check to see if the port of the pregenerated URL in your networking settings of the service is 8080.

If it is, I'd try setting it to an arbitrary number (eg, 3000), and change your application to listen to 3000 as well using the PORT variable.

Reference the variables here https://docs.railway.com/variables/reference and make sure that the port the app is running on (lets say 3000) is configured either in the railway deployment config (variables) or .env file or config file. Try comparing RAILWAY_TCP_APPLICATION_PORT with what you have configured and what your app actually uses.

go settings then scroll down to public networking. you will see which port its running (3000) click to edit then select port 8080