If you have already purchased the TurboTax Online edition, you do have to activate the product first.

To activate your TurboTax Online version, please visit this link. Select that "I have an account," log into your account, and proceed to the second step by adding your 16-digit activation code to review and activate the TurboTax Online product. Please note that TurboTax Online activation can only be linked to one account. 

Thank you for choosing TurboTax.