Fatal error: Uncaught mysqli_sql_exception: Access denied for user 'appuser'@'172.21.0.4' (using password: YES) in /var/www/html/index.php:2 Stack trace: #0 /var/www/html/index.php(2): mysqli->__construct('mysql', 'appuser', Object(SensitiveParameterValue), 'app') #1 {main} thrown in /var/www/html/index.php on line 2