To enable Google, Apple, and phone authentication in Firebase for your Flutter application, follow these steps:

7.1 Enable Google Sign-In in Firebase Console

• 7.1.1. Go to the Firebase Console.
• 7.1.2. Select “Authentication” from the left-hand menu.
• 7.1.3. Under the “Sign-in method” tab, enable Google.

7.2 Enable Apple Sign-In in Firebase Console:

• 7.2.1. Go to the Firebase Console.
• 7.2.2. Select “Authentication” from the left-hand menu.
• 7.2.3. Under the “Sign-in method” tab, enable Apple.

7.3 Enable Phone Authentication in Firebase Console:

• 7.3.1. Go to the Firebase Console.
• 7.3.2. Select “Authentication” from the left-hand menu.
• 7.3.3.Under the “Sign-in method” tab, enable Phone.