Please clarify that. What all did you do last year re: a 2019 return in Online TurboTax, and what is it you need to do now?
Download what??? Are you wanting to download a 2019 return PDF you prepared and filed in Online TurboTax last year?
Or are you wanting to download an unfinished 2019 return data file that you started last year in Online Premier and want to finish it in 2019 desktop software?
If you paid for 2019 Online TurboTax last year and need to finish a 2019 return, TurboTax Support should finish you the 2019 desktop software as a download.