They don't automatically transfer, and the pricing is different. Just start using TT Online, you only pay the fee when you are ready to file. Meanwhile, use the 60 day money back guarantee to get a refund of the price you paid for the desktop program.
https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-account-billing/turbotax-satisfac...
Or, you might be able to transfer the activation, but you would have to call customer support.
