You can set up a Facebook login for the mobile App that you have created. To use Facebook login you will need to make sure that you've registered your mobile app with Facebook and have an App Id.
If you already have the App Id, you can directly provide it in StoreHippo admin panel. Follow the
Go to https://developers.facebook.com and register yourself.
Click on Create App.
After entering the details, you can click on Add product in the sidebar. There you will see options like Facebook login, Audience network etc.
Click on Facebook login to setup Facebook login for your mobile app.
Select Android as the platform.
Go to step 3 by clicking on the Next button.
Enter the package name of your app. It would be in the format com.storehippo.app, in the Mobile App section in the StoreHippo Admin panel.
Enter the Default Activity Class Name as your package name with the application name in camelCase format i.e. com.storehippo.app.myApp.
Generating a Release Key Hash. If you have your custom key, then generate the hash of the key using the command shown on Facebook.
Enable Single Sign-On for Your App.
Fill up the form.
Go to the App Review section in the sidebar and make your app live for production use.
From the dashboard in the sidebar, copy the App ID and the name of the application.
Google Firebase re-signs your app with a new key on publishing. You must update your mobile app with the new signing key for the Facebook Login to work on your published.
Following are the steps
Copy SHA-1 certificate from there and as it's in hexadecimal and since Facebook needs it in base64 so use the command shown
echo SHA-1 key from step-2 (Hexadecimal) | xxd -r -p | openssl base64
This command won't work in command prompt use bash on windows or git cli.
Paste the base64 key in Facebook console => Settings => basic =