How to customize PDF file name

Hi,
You need to extend class Es_Property_Pdf and override output method. Change your pdf name there.
Then add this code in function.php of your child theme.

global $es_single_page_instance;

remove_action( 'wp', array( $es_single_page_instance, 'property_single_pdf' ) );

add_action( 'wp', 'my_pdf_output_action' );

function my_pdf_output_action() {
   $post_id = filter_input( INPUT_GET, 'es-pdf', FILTER_VALIDATE_INT );
   global $post;
   if ( $post_id && ( $post = get_post( $post_id ) ) ) {
      if ( $post->post_type == Es_Property::get_post_type_name() ) {
         setup_postdata( $post );
         global $es_property;

         $es_property = es_get_property( $post_id );

         include( ES_PLUGIN_PATH . ES_DS . 'classes' . ES_DS . 'class-property-pdf.php' );
         $pdf = new My_Extended_Pdf_Class( $post ); // Extended class of Es_Property_PDF
         $pdf->output();
         die;
      }
   }
}

My_Extended_Pdf_Class is your extended class

Hope it will help.

Thank you are trying to help me.
It isn’t clear for me, because I’m not a PHP programmer. Could you guide me further, please?