Fatal error: Uncaught TypeError: mysqli_insert_id(): Argument #1 ($mysql) must be of type mysqli, null given in /var/www/rn/form.php:6
Stack trace:
#0 /var/www/rn/form.php(6): mysqli_insert_id()
#1 /var/www/rn/index_pc.php(353): include('...')
#2 /var/www/rn/index.php(411): include('...')
#3 {main}
thrown in /var/www/rn/form.php on line 6