Customs declarations - invoice number - missing data

[bartairsoft]

In the customs declarations section of an order.

There is an invoice field but it is blank.

Please can you add automation to fill this field with the order number and allow a configuration setting to use field or not, and if used to use the order number which shipstation already knows about.

There is another box for duty, should this be a £0 rather than a blank?

Thanks

Frank