How to refresh PHP form

So here’s my problem:
I want to make a small quiz app using PHP, and here’s my code unitl now –

<?php
$questions = [
    ['What is 10 + 12?','23','19','22','21'],
    ['What is 19 + 21?','212','2','-15','40','80'],
    ['What is 3^4?','1987','27','81','33'],
    ['What is 2^5?','32','64','10','8']
];
$answers = ['21','40','81','32'];
$currentques = 1;
$index = $currentques - 1;
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Quizzes</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css">
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/jquery.slim.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/umd/popper.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js"></script>
</head>
<body>
    <div class="container border shadow" name="questiondiv" id="questiondiv">
        <form action="" method="POST">
            <p name="questiontext">
                <?php
                    echo $questions[$index][0];
                ?>
            </p>
            <?php
            $options = count($questions[$index]) - 1;
            for($i = 0;$i < $options;$i++)
            {
                $lindex = $i + 1;
                echo '<input type="radio" name="option" id="option'.strval($lindex).'">';
                echo '<label for="option'.strval($lindex).'">'.$questions[$index][$lindex].'</label><br>';
            }
            ?>
            <button type="submit" name="btnnext">Next</button>
        </form>
    </div>
</body>
</html>

When I click on the ‘Next’ button to submit the form, I want to save the answer (I know how to do that), change the $currentques value and then ‘refresh’ the form/dynamically generate it again, this time to show the next question and its respective options. This will go on until I reach the last question and create an array called $useranswers. I will compare this with my $answers array and generate a score.

I am confused regarding the ‘refresh’/re-dynamically generating part. I would be grateful for any help.