If you use the “Export CSV” button from the Daesalus Wallet you obtain a copy of your transaction history. You can drag and drop this into your Cardano Wallet in Koinly and it will import. Unfortunately, Koinly cannot interpret the timestamps correctly and only the Date is parsed correctly. The Time component is left to default to 12:00AM. This becomes a problem when matching transactions and you see duplicates rather than a proper match.
For example, the transaction in the Daedalus CSV export has this timestamp:
It was recognized as Sep 25, 2020 12:00 AM and not Sep 25, 2020 05:15.39 AM (UTC).
Please update your software to properly handle timestamps in this format such that the time is correctly parsed out and proper matching can occur.