// Add a new document in collection "cities"

db.collection("cities").doc("LA").set({

    name: "Los Angeles",

    state: "CA",

    country: "USA"

})

.then(() => {

    console.log("Document successfully written!");

})

.catch((error) => {

    console.error("Error writing document: ", error);

});

import { doc, setDoc } from "firebase/firestore"; 

​

// Add a new document in collection "cities"

await setDoc(doc(db, "cities", "LA"), {

  name: "Los Angeles",

  state: "CA",

  country: "USA"

});