got me?

If you have any old Facebook app,which allow to set the Enforce HTTPS to No ,set it to no and try again.
or add

if(is_ssl()===false)
 $redirecturl=preg_replace("/^http:/i", "https:", $redirecturl);

after the 5th line in authorization.php file, and when the facebook app redirect the site with https url of your site,remove the s from https and reload the url without modifying the other parameters in the url.(not recommended solution)

For new apps Enforce HTTPS is set to No and also no way to change it. Your only option is to migrate your site to https. (You need to do that anyway, because Chrome will start marking http sites as “unsafe” within few months).
LetsEncrypt is a free, automated, and open Certificate Authority that enable HTTPS on your website.
Hope it helps.
Thank you

I have two problems.

First the Set to NO option on the Enforce HTTPS is not working. It does not allow me to change that setting.

Second is I do not understand your instructions.
Where do I find this Authourization.php file?
When the facebook app redirects the site with the httpsurl of your site, remove s from the https and reload he url? How do I know when the facebook app redirects? Remove the S from where? Where am I at when I reload this thing and how do I do that? Where do I do this? Do I use an FTP and download the file then re-load it on my server? Is this something I do in facebook app on facebook?

I did look at the letsEncrypt stuff. That is a great resource. I am unsure if I can use it becasue I have no clue what they are talkign about either. But the concept is fantastic. Sure wish my host provider was one of the ones on thier list. I have 15 domains and 10 hosted sites. NO WAY I can move them all. I do not even know how to make my site HTTPS. I have a GeoTrust certificate on a few of my domains but would not have any idea how to make the entire site work with HTTPS..

So thank you for trying. I do not posses the knowledge to understand your instructions.

TA

That’s why i said old Facebook app, For new apps Enforce HTTPS is set to No and also no way to change it. To use facebook apps ,you must migrate your site to https. It’s not that complex as you think,so ask your service provider.
If you can’t do this,the only way is to follow this instructions.
Modify the authorization.php file as i mentioned,this file is located at the admin folder of the plugin file[../wp-content/plugins/facebook-auto-publish/admin].
After this,fill the app details as mentioned in the document how-can-i-create-facebook-application
In facebook settings page, you need to “Authorize” the account. (The authorization section is present in the wordpress plugin section).Then it will redirect to facebook popup dialog boxes(as shown in the document).After approving the app with permission,the facebook will redirect to plugin’s settings page in your site,that link contain encrypted code at the end of url ,the link will be starts like https://… you should change it to https://.. (ie removing only the s in https )and reload the url without modifying the other parameters in the url.
Then it will show a message like application is authorized.
Hope it helps.
Thank you.