Why is my "Facebook Like" field not appearing?

Your Facebook like box is most likely not appearing within your Entry Form because that Facebook page currently enforces Age or Country restrictions on their page. These restrictions will need to be removed for the like box to appear on your Entry Form.

Here is a link that should assist the admin of a Facebook page in removing Age or Country restrictions: https://www.facebook.com/help/778445532225441?helpref=faq_content

It is also possible that the Facebook page is not set to be Public. Here is a document that describes how a Facebook page can be made visible to the public.