facebook login error

I Have made all settings for the user to login using facebook but I am getting following errors. I am getting is log in with Facebook on my WordPress admin login page also and with this login , anyone who logs in with facebook becomes the administrator of the website. When I Try to login...

So, I am done with most of the technical setup for my web store and my fiance suggested I should also have social logins as no one these days want to fill up a form. Fair enough, checked the Facebook authorization in the help section and created the app however it shows me error every time I try...