Use the OpenID Connect (OIDC) module from the Marketplace. It’s a generic implementation of OIDC, which will work for Facebook login. Follow the installation and configuration instructions in the module.
You’ll need to register a web app in the Facebook developer portal, which will give you the client ID and secret that you need. Then facebook discovery endpoint (aka well-known config) is: https://www.facebook.com/.well-known/openid-configuration/
Next week the Mendix marketing team will be releasing a blog post about setting up “Sign in with Google” which is a very similar process. Look out for that!
Please go through open authenticator model which available on marketplace and go through the documentation