https://ww2.2019.turbotaxonline.intuit.ca/. This link does not work. I want to refile a 2019 return. Is there a working link to open and refile 2019 returns?

Unfortunately, TurboTax Online for 2019 is no longer available. 

If you need to make changes to your 2019 return, you can use the Canada Revenue Agency (CRA)’s My Account service to make the changes. Or you can print and mail a T1-ADJ T1 Adjustment Request form.