Navigate to the Account Providers Admin Page and click on Add.
Currently Available are: Facebook, Google, Microsoft Account, Office 365, Twitter, Linked In, PayPal, Instagram, My Digipass, any SAMLP or WS-FED capable provider and a built-in Username/Password HUB Provider.
The activate screen details the steps neccesary for the specific account provider.
In the case of an OAuth Account Provider (e.g. Facebook) you will have to define an App in de the development portal of the Account Provider and supply The Identity Hub with the Id and Secret of the App.
In case of the built-in Username/Password HUB Provider no configuration parameters need to be set.
Make sure Can be used to Sign In is checked. For more information on the "Can be used to Sign In" and "Can be used to link with" see How To: What is an Account Provider?.
Click Save. You will navigate to the list of Account Providers where the just activated Account Provider will be listed.