Changing the “Listings” header

You should be able to change it by adding the code below in your theme functions.php file or by using a plugin like Say What?

add_filter( "adverts_form_load", "customize_listing_title", 1000 );
function customize_listing_title( $form ) {
  if( $form['name'] != "advert" ) {
    return $form;
  }
  foreach( $form["field"] as $key => $field ) {
    if( $field["name"] == "payments_listing_type" ) {
        $form["field"][$key]["label"] = "A new label";
    }
  }
  return $form;
}