Quiz

The following script is simpler and works better:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.0/jquery.min.js"></script>
<script>
$(document).ready(function(){
    $("input.mod_quiz-next-nav").on("focus", function(){
        var r = confirm("Are you sure you want to go to the next page?\n• Click [OK] to go to the next page\n• Click [Cancel] to stay on this page");
        if (r == true) {
            $("input.mod_quiz-next-nav").blur()
            $("input.mod_quiz-next-nav").click()
        } else {
            $("input.mod_quiz-next-nav").blur()
        };
    });
});
</script>

You will find a second example with its XML on MoodleFormulas ↗.