First, please create a Facebook account for your institution.
Then go to this link https://developers.facebook.com/ and click on "Get started" in the top right-hand corner, then create your "Facebook for developers" account by following the instructions. Once the account has been created, click on "Create an App", choose "Consumer" as the app type, then enter your details.
In "Settings" then "General" you will find :
Your application ID
Your secret key
In "Settings", then "Advanced", in the "Share list of authorized redirection items" category, add the following URI :
Once you've completed these Facebook configuration steps, you'll need to return to the general settings to "Start verification" in "Verification".
Go to the CMS administrator area (_admin) and add a new user identification type to an existing or new population.
In "Authentication mode" choose "Facebook".
In "Customer identifier OpenId" and "Secret key" enter your ClientID and secret code respectively, as generated earlier. Then click on "Finish".
Your users can now log in using their Facebook account.