CryptoTrader.Tax only needs "Read" or "View" access to import your trade history. This permission protects your accounts. Learn more about API access in this article here.
Note 1: Due to a limitation in KuCoin's API, transactions before 2/18/2019 may not be imported.
If you traded on KuCoin before then you will need to make sure the API got all of your transactions. If it fails to do so, you can get trade history files that cover all years. Follow this guide to export your KuCoin files prior to 2/18/2019 and this guide for files after 2/18/2019. directly from the site or send a request for your complete trade history to the KuCoin support like it is explained here.
Note 2: main account and subaccounts
KuCoin main account API Keys can not access data from the KuCoin subaccounts. To import transactions from the subaccounts, log into every subaccount and create a new API Key. The process of creating a new API Key for the subaccount is exactly the same as for the main account.
Log in to your KuCoin account.
Click on the profile in the upper right corner and select API Management from the dropdown list.
Click on Create API.
Enter API Name and API Passphrase.
Set API Restrictions to General, to restrict your API Key only for getting transaction history.
Click No on IP Restriction so we can access your transaction history.
It is important to save API Passphrase somewhere because it can not be found later.
Enter Trading Password, Email Verification Code and 2-FA Code.
This window is displayed after successful security verification.
It is important to save API Secret and API Passphrase somewhere because they are visible only while creating the API Key.
Back in CryptoTrader.Tax, enter your Key, Secret, and Passphrase from earlier steps into their matching fields on the KuCoin tab and press Sync Transactions.