Go to Facebook Login for Android – Quickstart

1. Select an App or Create a New App 
2. Skip the step 2 (Download the Facebook App)
3. Skip the step 3 (Integrate the Facebook SDK)
4. Edit Your Resources and Manifest add this config in your android project
   • Open your /android/app/src/main/res/values/strings.xml file, or create one if it doesn’t exists.
   • Add the following (replacefacebook_app_name with your app name, facebook_app_id with your Facebook app id and facebook_client_token with your Facebook Client Token). 
5. Associate Your Package Name and Default Class with Your App. You must use your package name which one you gave in the previous step. 
6. Provide the Development and Release Key Hashes for Your App. 

To find info to how to generate you key hash go to https://developers.facebook.com/docs/facebook-login/android?locale=en_US#6–provide-the-development-and-release-key-hashes-for-your-app

Note: if your application uses Google Play App Signing then you should get certificate SHA-1 fingerprint from Google Play Console and convert it to base64

You should add key hashes for every build variants like release, debug, CI/CD, etc.

Facebook Login Setup is DONE!