Your Firebase project need to has:

• Authentication (by Google)
• Firestore
• Storage

And complete the following:

  1. Open your project settings.
  2. Firstore -> Indexes -> Single field.
  3. Press 'Add exemption' button and add the bellow fields.
  4. Collection ID: posts, Field path: createdAt; Check all checkboxes.
  5. Collection ID: posts, Field path: postId; Check all checkboxes.