Fatal error: Uncaught Error: Interface 'League\CommonMark\Extension\ExtensionInterface' not found in /home/kingelearn/public_html/vendor/league/commonmark/src/Extension/HeadingPermalink/HeadingPermalinkExtension.php:21 Stack trace: #0 {main} thrown in /home/kingelearn/public_html/vendor/league/commonmark/src/Extension/HeadingPermalink/HeadingPermalinkExtension.php on line 21