Fatal error: Uncaught Facebook\Exceptions\FacebookSDKException: Required "app_id" key not supplied in config and could not find fallback environment variable "FACEBOOK_APP_ID" in /usr/share/plumtex/latest/libs/vendor/facebook/graph-sdk/src/Facebook/Facebook.php:139 Stack trace: #0 /usr/share/plumtex/latest/shop/register-facebook.php(18): Facebook\Facebook->__construct(Array) #1 {main} thrown in /usr/share/plumtex/latest/libs/vendor/facebook/graph-sdk/src/Facebook/Facebook.php on line 139