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.
Login to your BitMart account.
Navigate to the API Management page.
Create a new API key with the name set as CTT and leave the IP white list empty.
Follow the instructions for entering your security codes on BitMart to finish creating the key and finally save your Access Key and Secret. This will be needed to run the importer.
Back inside of CryptoTrader.Tax, enter the Key, Secret, and Name created earlier. Once entered, click the Import Your Trades button to import.
Note: The BitMart importer will take a few minutes to run all the way through due to their rate limits.