Which "buy" does Koinly use when calculating CGT?

When Koinly calculates CGT, how does it decide which coins were sold?
e.g. if I buy 1 ETH at $1500 and later 1 ETH at $2000, then sell 1 ETH at $2200, am I taxed on a gain of $200, $700, or some conglomeration of the two?

Depends on the cost basis method in your settings