Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, null given in /home/hilair/public_html/ser/ser-list-cats.php:25 Stack trace: #0 /home/hilair/public_html/ser/ser-list-cats.php(25): mysqli_query() #1 {main} thrown in /home/hilair/public_html/ser/ser-list-cats.php on line 25