Facebook ordering is a plan add-on option. Please follow the facebook guide for app set-up and installation instructions.
Display Name - Must be entered exactly as it appears in Facebook.
App ID - Can be copied from Facebook.
Namespace - Must be entered exactly as it appears in Facebook.
Facebook URL - Once the above 3 fields have been entered, the Facebook URL will automatically be generated.
You have the option to skip this at the time of set-up, you can go back and enter the information once the Facebook app has been created.