rpress_customer_delivery_address

This filter is applied to use get customers’ delivery addresses, it includes one parameter.
$customer[‘delivery_address’] -> is an array containg delivery address.

An example of how you can append is below:

function add_validate_country_code( ) {
$customer['delivery_address'] = //get delivery address of customer
}
add_filter('rpress_customer_delivery_address', 'add_validate_country_code', 10, 1);