Firebase – How to pass Auth token in FireStore in Web app

I have developed a single crud project(Login screen and crud operation screen HTML) and hosted on firebase hosting. where User signing with email and password, I am using firebase signing with email and password and its working as expected.

But now issue is I want to secure backend with auth but its not passing auth in setDoc() deleteDoc() etc, My requirement is without auth. no one should do any operation on database.

import { doc, setDoc } from "firebase/firestore"; 
await setDoc(doc(db, "cities", "LA"), {
  name: "Los Angeles",
  state: "CA",
  country: "USA"
});

below rules are working but its not secured for production env. :

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if true
    }
  }
}

If set rules like below it give me insufficient permission error. I don’t know how to pass UID in setDoc() or any operation.

allow read, write: if request.auth != null

Update : If i put below code before setDoc() below code is not executing because currentUser has user data.

function addCity(){

    if (!firebase.auth().currentUser) {
        // this code not executing because user is signed
        alert("Login required");
        window.href = "login.html";
        return;
    }
    // i can print UID and it is showing means user is logged.
    await setDoc(doc(db, "cities", "LA"), {
         name: "Los Angeles",
         state: "CA",
         country: "USA"
    });
}