If you use Facebook Ads, however when viewing your Wicked Reports, you are not seeing Facebook costs, you will want to verify that your Facebook Authorization has not expired.
From time to time, the authorization that you provide Wicked Reports, expires. You should receive an email letting you know this. You can check by logging into http://my.wickedreports.com/authorizations and verifying that your Facebook is authorized
There is also the possibility that you have selected a time-frame in which the Ad you are seeing is no longer running. This could be the case if you are using First Click or First Optin attribution and a sale has occurred in which the customer's First Click or First Optin came from a Facebook Ad (and is no longer running). This is the beauty of Wicked Reports, you can see sales which occur now by which the customer's first click or First Optin was a Facebook Ad clicked potentially 3, 4 or 8 months ago.
NOTE: If you are seeing costs, but they don't match what you expect when comparing to the Ads Manager interface, please refer to this article on Why Facebook Ad costs in Wicked Reports might not match what Facebook's Ads Manager interface is reporting.
You will also want to verify that you have your Facebook Ads set up properly for tracking: Validate Facebook Ads and Update FB Ads From Wicked Reports