Warning: Undefined array key "card" in C:\xampp\htdocs\Validation\Site.php on line 4

Fatal error: Uncaught TypeError: Recognizer(): Argument #1 ($data) must be of type string, null given, called in C:\xampp\htdocs\Validation\Site.php on line 6 and defined in C:\xampp\htdocs\Validation\Site.php:33 Stack trace: #0 C:\xampp\htdocs\Validation\Site.php(6): Recognizer(NULL) #1 {main} thrown in C:\xampp\htdocs\Validation\Site.php on line 33