The config.php file contains the MySQL connection details.
On linux, this is often found at: /var/www/html/FOLDERNAME/config.php
'dbconfig' =>
array (
'db_host_name' => 'localhost',
'db_host_instance' => 'DBHOSTINSTANCE',
'db_user_name' => 'DBUSERNAME',
'db_password' => 'DBPASSWORD',
'db_name' => 'DBNAME',
'db_type' => 'mysql',
'db_port' => '',
'db_manager' => 'MysqliManager',
tags: #mysql #password #connection