Firebase Security
Starting from version 1.2.3, security rule of your firestore database must be moved to a product ready rules. Follow the guide below how want you need to do:
Go to firebase console, select the project from your list of projects.
Click on Firestore database
On the firestore database page, select rules at the top section/part of the page.
Now on the rules tab, copy and paste the code below
After pasting the rules above, click on Publish. Then you are good to go