My granddaughter activated the card on her computer to complete her return. How and where do I enter that activated code to do my return on my computer?

You can only use the Activation Code with one account. So if you want to share your Granddaughter’s code, you will need to use her account to prepare you returns. But you can do this through any computer that has an up to date browser.

You only need to enter your Activation Code once. If you try to enter it again, in the same account or in a different one, you'll get an error message, because the code has already been used. You can login using this page if you have already used your code: https://ww1.2020.turbotaxonline.intuit.ca/