It appears to me that there should be a Valid OAuth Redirect URL for the Facebook App to work. But there is no documentation on where that would be, or what that URL is.
Without a Valid OAuth Redirect URL this is the error message.
"Can't Load URL: The domain of this URL isn't included in the app's domains. To be able to load this URL, add all domains and subdomains of your app to the App Domains field in your app settings."
The domain is added in the App and is correct.
The Instagram account is a business account and is tied into the facebook page.
The Facebook App ID is filled out and so is the Facebook App Secret.
Please help.