Here to create…
Wandering through the journey in Flutter, and programming things not done before (at least in my knowledge 🙂), seeking for ideas until I stuck onto this post (Login into Facebook using Firebase)..

Let’s begin….
Getting started (with firebase) is simple,
- Go to https://firebase.google.com/
- Click Get started
- Register your app
NOTE : Please note that the name of your app should be same in the Firebase, your project’s manifest.xml and in the app-level build.gradle.
Go through this article, if not understood.
- A small advice, always fill the SHA certficate fingerprint, even though it says optional

- Go to

Click authentication and enable the fb sign in…It would ask you for AppID and AppSecret. (for which you have to register your app first in facebook developer console).
Documentation is concise and clear in the fb dev console. Important things to note are the steps:
Step 4. Edit Your Resources and Manifest
Step 5. Associate Your Package Name and Default Class with Your App
Step 6. Provide the Development and Release Key Hashes for Your App
From Step 7 to 10, you may skip them…
Last step,

Do copy the circled url in Facebook login settings (developer console)

Coming to Flutter side now,
Import the following packages,
flutter_facebook_login and firebase_auth

All setup, now programming part…………
On click of Sign in with Facebook, the following function is called :

On click of Sign out,

Now what special I did was to display all the details which came from firebase (like a boss )……

Video demonstration :
For complete source code, visit
https://github.com/AseemWangoo/flutter_programs/blob/master/FbSignIn.zip
P.S………………
You have brought up a very superb points, thanks for the post.
how about ios?
Hi Kelvin,
This should be applicable for iOS also….Any hicups, feel free to comment
Unfortunately flutter_facebook_login 3.0.0 broken in Flutter 1.17.
🙁