Warning: mysqli::__construct(): php_network_getaddresses: getaddrinfo for db failed: Temporary failure in name resolution in /var/www/html/db.php on line 72

Fatal error: Uncaught mysqli_sql_exception: php_network_getaddresses: getaddrinfo for db failed: Temporary failure in name resolution in /var/www/html/db.php:72 Stack trace: #0 /var/www/html/db.php(72): mysqli->__construct() #1 /var/www/html/index_menu.php(3): include('...') #2 /var/www/html/index.php(14): include('...') #3 {main} thrown in /var/www/html/db.php on line 72