Sure! I’d love to help you out. So, let me know your answers to the questions below:

1. Do you have a Firebase account?
2. If you have a Firebase account, did you update the firebase.js file properly with the configuration values from your Firebase account?

If your answer to the questions above is yes and the issue still persists, let me know how you set up your project.

I encountered that error as well when I didn’t set my Firebase configuration properly:

const firebaseConfig = {
    apiKey: "AIzaXXXXXX",
    authDomain: "expo-firebase-phone-auth-XXXXXXX.firebaseapp.com",
    databaseURL: "https://expo-firebase-phone-auth-XXXXXXX.firebaseio.com",
    projectId: "expo-firebase-phone-auth-XXXXXXX",
    storageBucket: "expo-firebase-phone-auth-XXXXXXX.appspot.com",
    messagingSenderId: "XXXXXX",
    appId: "1:XXXXXXX:web:a1XXXXXXX",
    measurementId: "G-XXXXXXX"
};

Let me know! Hope it helps.