If you have set up quiz points on your form, then you simply have to go to Field/Form rules you’ll find the Quiz score field on the bottom part of the first dropdown list within the rule. The quiz score will change in real-time if the form user selects other options on the quiz before submission.
The only operators that are available for the quiz score are: is, is greater than, is less than.
Here is an example:
This is a form rule that redirects form users to a web page on submission if they scored over 70 points on the quiz. Here you can add the URL of a downloadable document, such as a certificate.