Here's what you need to do
The first and usually only step is to download all your transaction data from Theta and upload them to Koinly. There are a couple of ways to do this:
Note that if you decide to use CSV files, you have to make sure to import your deposits/withdrawals and trades for all previous years— not just the current one!
That's it. The only other thing to keep in mind is to tag your airdrops/forks so they show up as Income on your final cryptocurrency tax reports!