you don't need the 2019 AGI. Turbotax has permanently closed online preparation and e-filing of the 2020 return.
you would need to buy the CD or a download of the 2020 product for installation on a full PC or MAC. mobile phones won't work.
system requirements
https://turbotax.intuit.com/personal-taxes/cd-download/tta-system-requirements
you can buy from Turbotax or other websites but be wary of sites that offer steep discounts.
turbotax
https://turbotax.intuit.com/personal-taxes/past-years-products/2020/
