you don't need a win 10 computer if you use the online version of TT for your 2020 return. otherwise unless TT changes it's mind you'll have to find another option.
I use desktop because I have to prepare family returns. what i did was buy a 120GB SSD which i loaded win 10 on (free download from MS) just to do tax return. created dual boot. fater finishing deleted dual boot and removed drive though technically could disable thru BIOS.