Added additional customs data. Added hook which fires in case label r…

…equest errored.

src/Labels/Label.php

@@ -839,6 +839,7 @@ public function get_customs_data( $max_desc_length = 255 ) {
 					'gross_weight_in_g'   => $item_gross_weights[ $key ],
 					'single_value'        => $product_value,
 					'value'               => wc_format_decimal( $product_value * $item->get_quantity(), 2 ),
+					'sku'                 => $item->get_sku(),
 				),
 				$item,
 				$shipment,

src/ShippingProvider/Auto.php

@@ -1092,6 +1092,8 @@ public function create_label( $shipment, $props = false ) {
 						}
 					}
 
+					do_action( "{$this->get_general_hook_prefix()}error_while_creating_label", $label, $result, $this );
+
 					return $result;
 				}
 			}