Fatal error: Uncaught Error: Call to undefined function iberezansky\fb3d\get_header() in C:\xampp\htdocs\info\wp-content\plugins\interactive-3d-flipbook-powered-physics-engine\assets\templates\single-3d-flip-book.php:4 Stack trace: #0 {main} thrown in C:\xampp\htdocs\info\wp-content\plugins\interactive-3d-flipbook-powered-physics-engine\assets\templates\single-3d-flip-book.php on line 4