React-Native: "FirebaseError: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app/no-app)"

I'm building a React Native app, currently trying to implement an authentication registration system through Firebase Auth. I've followed a guide/the docs on the website to setup the Firebase config file. I run the app, enter a email and password, when I click the signup button I'm given the follow error below:

FirebaseError: Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app/no-app).

I've search on google for possible fixes yet nothing seems to work. I've initialized Firebase as per the docs/tutorials I've watched. Hopefully someone can shed some light on the matter. I'll include the config file code below, XXXX to replace my actual config info

firebase.js

import * as firebase from 'firebase/app';
import "firebase/auth";

const firebaseConfig = {
  apiKey: "XXXX",
  authDomain: "XXXX",
  databaseURL: "XXXX",
  projectId: "XXXX",
  storageBucket: "XXXX",
  messagingSenderId: "XXXX",
  appId: "XXXX",
  measurementId: "XXXX"
};

firebase.initializeApp(firebaseConfig);

api.js

export function registerUser({email, password}) {
  firebase
    .auth()
    .createUserWithEmailAndPassword(email, password)
    .catch(function(error) {
      console.log(error);
    });
};