Warning: Undefined variable $mysqli in /var/www/html/include/header.php on line 126

Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, null given in /var/www/html/include/header.php:126 Stack trace: #0 /var/www/html/include/header.php(126): mysqli_query(NULL, 'SELECT * FROM c...') #1 /var/www/html/terms-and-conditions.php(2): include('/var/www/html/i...') #2 {main} thrown in /var/www/html/include/header.php on line 126