Buying the Desktop program won't unlock an Online return. You need to pay for a 2018 online account in Plus or higher to unlock it. You need to call in next week and ask them to unlock it. Or pay for 2018 right away. What is the status of your 2018 return? Have you filed it? Did you use the Free Edition?
Contact Customer Service 5am-5pm Pacific M-F
https://support.turbotax.intuit.com/contact/
