ip module returning different ip addresses - node.js

Question

I am using the ip library of npm.
I have two config files, one for React and one for Node, for the same application.
const ip = require('ip');
console.log(ip.address());
This returns different ip addresses for the React config file(inside the src folder-127.0.0.1) and Node server file(outside the src folder - IPv4 address).
The issue is that I am pretty sure that I ran the exact same code earlier and it gave me the same ip addresses for both as then I was able to access my webpages. I need the same ip to make requests to my node backend, I cannot afford it in production. Are there other definite methods of doing this?

Answer 1

You get different ip results because 2 method call ip.address() are using different network interfaces.
To make ip.address() return identical result, you can pass network interface name as the first parameter, such as en0:
const ip = require('ip');
console.log(ip.address('en0'));
p.s. To get all current networks interface names, os.networkInterfaces() can be used.
Update: OP try to get IP address in React code, in browser side. This is mission impossible. Otherwise, it would bring huge security problem.
Update 2: OP don't want to store endpoint IP address in frontend code for security reason, neither want to retrieve the IP address first (network overhead issue). In this case, you can make a proxy in server. All frontend know is interacting with current server, the data exchange is delivered by server as:
Browser <--> Server <--> Various endpoint IP
The steps are:
The server (that host the frontend code) get request from browser
Server check which endpoint would be used for that client
Server send the request to specific endpoint
Server get response from endpoint
Server return the response in above step to browser