Click on the Get started button (this may not be visible if you have already set up other forms of Authentication).
Select the Sign-in method tab.
Click on Google (Under the Additional Providers section). If you have already added any other provider, click on the Add new provider and then click on Google.
Find the Google switch and enable it.
Input your Project public-facing name and project support email.
Click on the Save button.
Enabling Google sign-In in Firebase
2. Creating a Google sign-in button
To allow users to authenticate using their Google account, you need a login page with a button. FlutterFlow provides a collection of ready-to-use templates. Let’s use the login and signup template.
To create a new page:
Click on the Select Page or Component from the Navigation Menu (left side of your screen).
Click on + Create New, Give it a name and then click on the Auth tab.
Find the Login & Signup #3 template and click on the Use Template button.
Now, drag the IconButton widget from the Base Elements tab (in the Widget Panel) or add it directly from the widget tree inside the Column (under the Sign In tab).
Keep the IconButton selected and move to Property editor. Click on the Add Box Outlined + button, then search and select the icon name with FontAwesome.google. Also, set the background color using the Fill Color property.
Creating a Google sign-in button
2.1 Adding a login action
To login a user on click of Login button:
Select the IconButton (with Google logo)from the widget tree or from the canvas area.
Click on the Actions tab (on the right side of your screen).
Click on + Add Action and select the On Tap option.
Find the Action Type dropdown and change it to Authentication.
Find another Action Type dropdown below, and change it to the Login.
Click on the Auth Provider dropdown and set it to Google.
Now, checkmark the Create User Document checkbox.
From the Collection dropdown below, select the users collection.
Adding a login action
3. Create an action to logout
To log out a user, you can place a button on your home page and add the Logout action.
Google Sign In functionality does not work in Run Mode and can only be tested on a real device or emulator. To deploy and test the Google authentication, you will need to download the code and run it in your IDE.