Using the .CSV you generated from Stitch Labs, you can perform a migration of data through a 4 step process.
1. Find or create order relationship (company, contact + addresses)
2. Find or create order line items as variants in TradeGecko
3. Find or create order currency in TradeGecko
4. Create an order referencing 1, 2, and 3.
Do note that the data in the .CSV does not provide the level of detail TradeGecko needs in order to accurately migrate the data from Stitch Labs. It is advised that you reach out to our friendly Gecko Gurus to help you with this request who will be able to advise you accordingly.