You bought the 2019 Desktop program? Then you should use that this year. Next year when you do 2020 you can use the Online version and transfer the .tax2019 file from your computer to the online version.
If you want to use online for 2019 you need to get a refund for the Desktop program and pay for online separately. Online and Desktop are completely separate and have different pricing and features.
If you used the Desktop program before you probably won't like the Online version. The Online versions are only good for one return per account. And you may need to upgrade to a higher version to enter certain things. You can't see or enter into the actual forms.
You can access an online return from any computer and device. Your return is stored at Turbo Tax. So be sure to download the pdf and .tax files to your computer when you are done or you may not be able to access it when you need a copy. Or if you ever need to amend.
