Setup database

Adding Firestore indexes

Go to Firestore in Firebase admin panel

Click on "Add index" and add following index:

In the bottom of the form in "Query scopes" field select "Collection" option.

After filling form click "Create index"

Let's setup firestore rules. Go to rules tab and replace existing rules with following:

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read;
      allow write: if request.auth != null;
    }
  }
}