When dropshipping products from AliExpress, we recommend adding a custom note to the suppliers informing that you are dropshipping as there is a risk that the suppliers will add some promotional material or order invoices in the package.
Default Message
Go to Bestdealer - Setting on the bottom left of BestDealer and click the Other, and find the Leave a message to AliExpress sellers box.
Also, you can edit a message in specific order, just go to the order page and click "Message"
You can write a message to your supplier, it will be sent to your suppliers with each order you send to AliExpress or with BestDealer sourcing.