Fatal error: Uncaught Error: Class "Facebook\Helpers\FacebookSignedRequestFromInputHelper" not found in /opt/app-root/src/wp-content/plugins/xyz-wp-smap/api/Facebook/Helpers/FacebookCanvasHelper.php:31 Stack trace: #0 {main} thrown in /opt/app-root/src/wp-content/plugins/xyz-wp-smap/api/Facebook/Helpers/FacebookCanvasHelper.php on line 31