This filter is applied to use the retrieved payment user info, it is including two parameters.
$user_info -> is to get user info.
$ID -> is used to get id.
An example of how you can append additional information:
function get_payment_meta_user_info( $user_info ) {
// it returns user info.
return $user_info;
}
add_filter( 'rpress_payment_meta_user_info', 'get_payment_meta_user_info',10,2 );