You can still download a CSV from Kucoin, when your open the old version https://www.kucoin.com/records-v1. Otherwise the KuCoin support will provide you with the file. Possibly the file come with a two separate tabs. So you need to split the file and create to separate CSV files. One for the trades and one for the deposit and withdrawal transactions.
Then you can import the KuCoin CSV on "Custom Exchange Import" page, and follow this setting for the trade transactions:
For the deposit and withdrawal transaction file please use these settings:
You can save the settings for each file for later usage as well.
There are new files available at KuCoin. For those we can not use Custom Import to import all the data all at once. This is because some of the fees need to be added to the SELL amount and some others need to be deducted from the BUY amount.