Set up Facebook comment moderation for your site to enable you to edit or delete comments that are posted on the sites you build.
Facebook changes their developer interface quite often, but the steps below are usually similar. You need to set up the app on Facebook and insert a code into your header.
Go to https://developers.facebook.com/apps, and click Add a New App.
If you are prompted to select a platform, select Website.
On the next page, it will ask you to create a new Facebook App ID. You can choose to go through the quick start process to be more organized, or you can click Skip and create App ID at the top right.
Complete all the required fields and click Create App ID.
After you have finished, it will take you to the App Dashboard. If you do not see this screen, click My Apps or View my App Dashboard to see this screen.
In the top navigation, click the Products tab, then click Social Plugins.
Scroll to the bottom of this page, and under Social Plugins Documentation, click Comments.
Click Moderation Setup Instructions.
You should now see the code for enabling Facebook Comments Moderation. Copy all of the <meta> code for your app, as shown below:
After copying the code, open your editor. In the left panel, click Settings, and then click Header HTML.
Paste your code in the space provided, and click Save.
You are now able to moderate Facebook comments made on your site. You can either moderate it within the page itself or you can moderate it within the Facebook app settings (click Moderation Tool in the comments plugin).
If you followed all of the steps above (which includes installing the code in your header), and the moderation is not working, it might be that Facebook is caching your site without the moderation tool. Use their debug tool here: https://developers.facebook.com/tools/debug/.
When you debug/scrape your page, it should show your Facebook app ID—if it does not, you haven't included this on your site correctly.