TL:DR How to track pixel conversions on quizzes
Set up a custom page on your website for the cover page of your quiz (not interact) yoursite.com/quiz - this lets you track views
Set up another page on your site where you embed the quiz with the cover turned off yoursite.com/take-quiz - this lets you track starts
You will not be able to track people who drop through the quiz questions
Set up different pages on your site for each quiz result and redirect the results to those pages yoursite.com/quiz-result-title - this will let you track completions and who got which result
(Optional) set up different opt-in forms on your own site using your own URLs so you can track who converted from which result yoursite.com/result-opt-in
First: Create result pages for each quiz outcome on your website, include the word "result" in each outcome page URL
Set up a URL on your site for each of your quiz outcomes, then set up quiz outcome redirect so traffic goes to your URLs once someone completes the quiz.
Here's my URLs, you'll see the word "result" is in each URL.
joshhaynam.com/quiz-result-you-could-save-a-little
joshhaynam.com/quiz-result-you-could-save-a-good-amount
joshhaynam.com/quiz-result-you-could-save-a-lot
And here's how the setup looks inside of Interact.
Note: When using Lead Generation for your quiz the results pages are seen after someone opts-in, we recommend leaving the opt-in optional, which means results can be seen without opting in. You can force the opt-in which means someone would only reach the results if they have opted in, but we do not recommend it.
Second: Create Custom conversion where URL contains “result”
Here's the doc on Setting up Meta Custom Conversion. You are going to set up a URL rule where the URL contains the word "result"
Now you will have a Custom Conversion Event that fires when someone reaches any outcome page of your quiz and if you have Lead Generation enabled on your quiz you will be able to track cost per lead using this method.