How to access second node application on same server?

Hi there! Sorry if this was asked already; I searched for quite some time, but did not manage to find a solution to my issue.

In a nutshell I’m trying to send http request from my one nodejs application to the other, both residing on the same digitalocean server. (localhost:8080 and localhost:3000) Only localhost 8080 is meant to be accessed from the outside, 3000 is an API that could remain local to the server.

However when executing those queries, they are not received.

I might be off with my understanding, but the same setup up is working on my local machine, shouldn’t that be true for the server as well? Is there a reason why you would not be able to access a second nodejs app locally?

I’m a weird engineer doing programming, so please have mercy with my soul and I would appreciate any help especially if it includes some explanations about network fundamentals.

Thank you so much already!