Context:

My app makes use of VoIP using TwiML, I store call records and additional data in Firebase. When a call is created, Twilio is a central point where the call gets created/cancelled. For this reason, when making a call I make use of Firebase to create a call entry in Firebase.

Looked for some documentation online for this issue, support or similar issues but came up short. The issue is quite simple:

Log output:

I see log output up to this message:

getting profile from

then get this error:

UnhandledPromiseRejectionWarning: Unhandled promise rejection: Error: Could not load the default credentials. Browse to https://cloud.google.com/docs/authentication/getting-started for more information. at GoogleAuth.getApplicationDefaultAsync (/var/task/node_modules/google-auth-library/build/src/auth/googleauth.js:180:19) at processTicksAndRejections (internal/process/task_queues.js:97:5) at async GoogleAuth.getClient (/var/task/node_modules/google-auth-library/build/src/auth/goo...

TwiML app code similar to Firebase Functions:

const AccessToken = require('twilio').jwt.AccessToken;
const VoiceGrant = AccessToken.VoiceGrant;
const VoiceResponse = require('twilio').twiml.VoiceResponse;

// Import the functions you need from the SDKs you need
const firebase = require("firebase-admin")

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

// Initialize Firebase
console.log("initializing firebase")
const app = firebase.initializeApp(firebaseConfig);

exports.handler = async function(context, event, callback) {
    console.log("Running make-call")
    const from = event.From;
    let to = event.to;
    //...

    console.log("getting profile from")
    // exception is thrown at this line below
    var callerProfileSnap = await firebase.firestore(app).collection("profiles").doc(from).get();

    // originally had this, but attempted loading the app manually as "credentials" couldn't be loaded made me think this might be an issue
    // var callerProfileSnap = await firebase.firestore().collection("profiles").doc(from).get();

    // ... continuation of code

    var voiceResponse;
    callback(null, voiceResponse);
}

Any idea what can cause this/why this occurs? Not finding much in the way of solutions online