I'm a fellow user, but you should be able to. You shouldn't have to pay for 2 products. Especially if you are within the 60-day moneyback guarantee window for the desktop software. If you bought directly from TurboTax or from one of their authorized retailers, you can request your refund online with the form in the FAQ below. You can also track your product refund request using that same interface (tiny blue link at the bottom of it).
In the form you can tell them the problem you had activating it and used the Online TurboTax instead.
FAQ: How do I request a refund for my TurboTax product?
https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-refunds/request-refund-turbotax-product/L834M6uyW_US_en_US