Im trying so sav data on firestore through react native but when I press the buttom to save data, I get "Possible unhandled promise rejection (id:1); I dont know what else to do. Thanks. There my code below.

My code in App.js

async function submit() {
    await db.collection("cities").add({
      name: "Tokyo",
      country: "Japan",
    });
  }  

My Firebase code

import { initializeApp } from "firebase/app";
import { getFirestore } from "firebase/firestore";

const firebaseConfig = {
  apiKey: "xxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
  authDomain: "xxxxxxxxxxxxxxxxxxxx",
  projectId: "xxxxxxxxxxxxxxxxxxxxxxxxxx",
  storageBucket: "xxxxxxxxxxxxxxxxxxxxxxxx",
  messagingSenderId: "xxxxxxxxxxxxxxx",
  appId: "xxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
};

const app = initializeApp(firebaseConfig);

const db = getFirestore(app);

export default db;