When or where does turbotax ask if I have an account with Itsdeductible online?

To enter charitable donations -

Click on Federal Taxes (Personal using Home and Business)
Click on Deductions and Credits
Click on I'll choose what I work on (if shown)
Scroll down to Charitable Donations
On Import from ItsDeductible Online, click on the start or update button

Or enter charitable donation in the Search box located in the upper right of the online program screen. Click on Jump to charitable donation