Secure Your Firebase Project
Firebase Security Rules
By default, Firebase Rules allows anyone to access your data. This can be problematic if you don't want data to be stolen or illegally modified.
Firebase Security Rules are required for Firebase Realtime Database, Firestore and Firebase Cloud Storage to protect its data.
Firebase Security Rules are special conditions that can restrict which data can be read or write, when and by whom.
It can allow only a group of authorized people to access your data.
Members get customized Security Rules for their project.
Become a member: https://www.buymeacoffee.com/sparsha
Restricting API Key
Restricting API Keys disallow others to run an app on their own Website using your Firebase API Keys.
(However, this doesn't make your Database or Cloud Storage secure. Any programmer can still steal your data easily. To Secure your Database and Cloud Storage, you need to deploy Firebase Security Rules for your app.)
3. Select an Application restriction controls
4. Add an item