If you've connected your API on the Trading Tab, but are not seeing your trades imported, please make sure you have clicked the "Import Trades" button that will appear after linking your API:
It's important to make sure you have the correct tax year selected in your account. If you receive a different error when connecting your API, please email us at support@bitcoin.tax and include the error, as well any additional information that will allow us to assist you (e.g., exchange name, volume of trades, etc.).