Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, null given in /var/www/html/home/course/index.php:62
Stack trace:
#0 /var/www/html/home/course/index.php(62): mysqli_query()
#1 {main}
thrown in /var/www/html/home/course/index.php on line 62