This TurboTax FAQ tells you how you can submit a claim under the TurboTax 100% Accurate Calculations Guarantee: https://turbotax.community.intuit.ca/turbotax-support/en-ca/help-article/tax-return/submit-claim-tur...

Thank you for choosing TurboTax.

That link says:

Step 2

1. Go to our Contact Us page.
2. Follow the prompts and enter your information. Once you've entered your info, a phone number and incident ID will appear. Make a note of your incident ID.Call the number provided. A specialist will process your claim.

But there are no prompts on the Contact Us page or any place to enter information on the contact us page that I can see. Where do I find the prompts to enter the information and get an incident ID?

Go to our Contact Us page. and enter your phone number; once you get connected to a product support, you can ask them for a case number.