If your Elasticsearch server requires a different HTTP basic authentication username and password to write to index, you may provide the password here. Note: The core Elasticsearch software itself does not provide username or password features, but you may achieve this functionality by using a plugin, such as Search Guard, or by accessing it through a proxy.
This setting cannot be changed through the web interface. You may change it by setting a value in your config.php file for the following config variable:
$cfg->plugin_search_elasticsearch_password
.