Here's what you should do
The first step is to download all your transaction data from bitmarket and upload them to Koinly. There are a few ways you can do that:
Note that if you want to use CSV files, you must make sure to import your deposits/withdrawals and trades for ALL previous years - not just the current one!
That's it. Don't forget to tag your airdrops/forks so they show up as Income on your generated cryptocurrency tax documents!