Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, null given in /home/zebuzebu/englishmusicacademy/calendarinc.php:40 Stack trace: #0 /home/zebuzebu/englishmusicacademy/calendarinc.php(40): mysqli_query(NULL, 'select * from b...') #1 /home/zebuzebu/englishmusicacademy/topcode.php(747): getBookedOnesInfo('2023', '12') #2 /home/zebuzebu/englishmusicacademy/index.php(17): include('/home/zebuzebu/...') #3 {main} thrown in /home/zebuzebu/englishmusicacademy/calendarinc.php on line 40