If you're getting Turbotax for free from Fidelity, it is downloadable. You just need to go to the correct place on the Turbotax site to do it...and it prompts you for a $0 charge. Lots of folks here do it - I do every year. No issues. I never use the web version, only install on my computer.
As far as how the tax lots are handled, my understanding, similar to stock trades, you need to take care of this on your brokers site before the trades settle. If you don't, then when the broker issues your 1099 and forwards to the IRS, they are going to calculate your profit/loss based on what you have set in your account for the default way of handling it. On Fidelity, I have a default scheme set. However, if I want, when placing a sell, I can assign the tax lots in the transaction, or after the trade but before settlement go in to the cost basis screen and manually change the tax lot. I know it is the same on TD and Merrill Edge, and I believe it is the same on Etrade as well. After the trade settles, that's it - you can't change and however they marked it, is how profit/loss will be reported to the IRS and you need to have the profit/loss in your tax forms match, or it may raise red flags.
I would guess that whoever your broker is for the crypto trades also provides this ability to have a default method, or identify the tax lots at the time of the sells or before settlement.