OAuth2 for Paypal.

Add client_id and client_secret to your configuration: config :ueberauth, Ueberauth.Strategy.Facebook.OAuth, client_id: System.get_env(“PAYPAL_CLIENT_ID”), client_secret: System.get_env(“PAYPAL_CLIENT_SECRET”) sandbox: false #default

Do note that you can pass a sandbox: true option in this config to use the paypal sandbox for authentication, by default this is false.