As of February 5th, 2018, Facebook requires a business page to have 2,000+ likes in order for any third party applications to integrate with it.
Because of this restriction, you will not be able to activate Facebook Connect unless your business page has 2,000+ likes.
If you attempt to connect a business page that does not meet this requirement, you'll see, "Page ID is required. Page URL is required."
Add a call-to-action button as an alternative way to add MassageBook booking options to it. To learn more, go here.