Create a Facebook client

To use Facebook as an Identity Provider, visit the Facebook for Developers page, and follow these steps:

Generate a key hash

The default password for Android Studio is android.

To generate a key hash value, in a terminal window, enter the following command:

keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore | openssl sha1 -binary | openssl base64

On the developer apps page, double-click an Android app.
In the left navigation panel, select Settings > Basic.
At the bottom of the page, click Add platform, select Android, and click Next.
In the Select Android Store dialog, select a store.

For example, Google Play.
Click Next.
Scroll down to the Android section.
In the Key hashes field, enter the key hash value you generated earlier.
In the Package Names field, enter your app’s Google Play Package Name.

The name is often a reverse domain name, such as com.example.app.
In the Class Name field, enter your app’s class name.
Click Save changes.

On the developer apps page, select iOS.
Click Next.
Enter your Bundle ID.

The name is often a reverse domain name, such as com.example.app.
Click Save changes.
In the left navigation panel, under Facebook Login, select Quickstart.
Click iOS.
Read the information, and select your package manager.
Click Next.
Enter your Bundle ID.
Click Save.
Click Continue.
Select your single sign-on settings.
When you get to Configure Your info.plist, configure your info.plist file with the XML snippet that contains data for your app.