Send invoices for unpaid orders and "mark as paid"

In 3Dsellers Orders, an unpaid order's More Actions menu has two actions: Mark as paid and Send eBay Invoice.

Mark as paid and Send eBay Invoice work only on unpaid orders. Send eBay Invoice is for eBay orders and is greyed once the invoice was sent.

For the full steps, see Add Tracking Numbers and Mark eBay Orders Shipped or Paid.