I switched to CD/Desktop this year
I don't know if you're aware of this or not, but that means you would need to download the .tax2019 file from your online account and place it in the documents/turbotax directory, before you even started your 2020 tax return. That would be the only way possible for you to import the historical data from the 2019 tax return, into the 2020 tax return.
The import must be done at the very beginning of the 2020 return. You can't import it once you've passed the screen giving the option to import, unless you delete the .tax2020 file and start over from scratch.
Since you're using Home and Business, that tells me that the first thing you're dealing with "is" the rental property. So it's not like you already have a whole bunch of other stuff you already entered into the 2020 program. Therefore, I see starting over from scratch as a viable option, if you want. Of course, that's only if you can actually get the .tax2019 file out of your online account, without having to pay for it.
