Fatal error: Uncaught Error: Call to undefined method Book::getAuthorBySlug() in /home/allwokfe/public_html/app/Controllers/AuthorController.php:8 Stack trace: #0 /home/allwokfe/public_html/index.php(81): AuthorController->show() #1 /home/allwokfe/public_html/app/Core/Router.php(59): {closure}() #2 /home/allwokfe/public_html/index.php(230): Router->dispatch() #3 {main} thrown in /home/allwokfe/public_html/app/Controllers/AuthorController.php on line 8