Warning: Trying to access array offset on value of type null in /home/videoloop2/loop.la/escuela_curso.php on line 12

Fatal error: Uncaught TypeError: array_key_exists(): Argument #2 ($array) must be of type array, null given in /home/videoloop2/loop.la/escuela_curso.php:12 Stack trace: #0 {main} thrown in /home/videoloop2/loop.la/escuela_curso.php on line 12