Fatal error: Uncaught exception 'Facebook\Exceptions\FacebookSDKException' with message 'Required "app_id" key not supplied in config and could not find fallback environment variable "FACEBOOK_APP_ID"' in /var/www/vhosts/datmachin.com/httpdocs/Facebook/Facebook.php:139 Stack trace: #0 /var/www/vhosts/datmachin.com/httpdocs/controllers/cUser.php(51): Facebook\Facebook->__construct(Array) #1 /var/www/vhosts/datmachin.com/httpdocs/index.php(19): cUser->loginWithFacebook() #2 {main} thrown in /var/www/vhosts/datmachin.com/httpdocs/Facebook/Facebook.php on line 139