在调用PHP函数的AJAX请求之后，在表单提交时重定向页面

I have an HTML page (index.html) that collects an email address and submits it to a server via an AJAX POST request. When the submit button is clicked, a javascript function executes the post request via AJAX and then the page submits to itself. I need to modify this so that the page submits to another page (thankyou.html) instead of to itself. I'm not sure how to do this in PHP. Is there a way to redirect a PHP page once a form is submitted and the AJAX query is executed?

I'm not sure if I should redirect the page in Javascript or in HTML or in PHP.

This is the form in index.html:

       <form class="email-form" method="POST" validate>
            <div class="email-input-container register-info-email">
                <input class="email-input" type="email" autocapitalize="off" autocorrect="off" autocomplete="off" required name="MERGE0" id="MERGE0" placeholder="Email Address" pattern="[a-z0-9._%+-]+@[a-z0-9-]+\.[a-z]{2,63}$" aria-label="Email Address">
                <input id="sub-button" type="submit" class="submit-button" value="Submit" >
                <span class="success-message"><span class="sr-only">We got you</span></span>
            </div>
        </form>

This is the post request in PHP (post.php)

if ( isset($_POST['email']) ) :

    $data = [
            'email' => $_POST['email']
    ];

    if ( isset($_POST['platform']) ) :

            $data["device"] = $_POST['platform'];

    endif;

    syncMailchimp($data);

endif;

This is the AJAX request:

        $.ajax({
            type: "POST",
            url: 'post.php',
            data: data,
            success: function(data, status) {

                var message = JSON.parse(data).message;

                if (message == "error") {

                    $('.email-form small').html('An error has occurred. Please try submitting again.');
                    smallHighlight();

                } else if (message == "subscribed") {

                    $('.email-form small').html('You are already subscribed');
                    smallHighlight();

                } else {

                    $('.email-form').addClass('form-success');
                    $('.email-form small').attr('style', '');

                }

            },

If you want to redirect to another page, put this after form is successfully submited

window.location = "http://www.example.com/thankyou.html";

EDIT: You shouldn't handle this redirect in PHP, because this is asynchronous call. You need to reference this somehow in you submit script

Hope it helps

In PHP you can use this.

header('Location: http://www.example.com/thankyou.html');

and In Javascript

window.location.replace("http://www.example.com/thankyou.html");

or

window.location.href = "http://www.example.com/thankyou.html";