You can download your transaction history from blockchain.com in the CSV format.
1. From the home page of the exchange click the settings gear in the upper right corner.
2. Select order history in the drop-down.
3. On the order history page choose the year and your full trade history is automatically sent to your email.
a. Select deposits and the year to receive that file.
b. Select withdrawals and the year for that emailed file.
4. Open the Blockchain.com message in your email and click "Download Now" to get your transaction history file.
5. Now that you have your CSV file, you can import it into your TaxBit account. HERE is a link to a guide for accomplishing that if you need to do so.