Warning: mysqli::__construct(): php_network_getaddresses: getaddrinfo for db failed: Name or service not known in /var/www/html/src/db.php on line 10

Fatal error: Uncaught mysqli_sql_exception: php_network_getaddresses: getaddrinfo for db failed: Name or service not known in /var/www/html/src/db.php:10 Stack trace: #0 /var/www/html/src/db.php(10): mysqli->__construct() #1 /var/www/html/src/index.php(4): include('...') #2 {main} thrown in /var/www/html/src/db.php on line 10