If you’d like to direct learners to start over a mini-course when their performance have been unsatisfactory, you can use a conditional completion card. In this card, you can create conditional messages for different scores.
For example, you ask five quiz questions and two or fewer correct answers mean “unsuccessful”. Here is an example of creating a condition for this specific case.
Unfortunately, CTA link buttons cannot be added to conditional messages. But still, you can create an attractive link by creating a hyperlink. You can use the URL of the same mini-course for this.
In completion cards, there are no next buttons. Here's how this looks to a learner: